Thanks for your long and thoughtful post.
I do wonder though if you are confusing bitcoin as a currency with other financial services. Reading through your post I think there are three themes in what you are saying:
A) bitcoin is not as secure as credit cards.
Bitcoin is like cash rather than a credit card. Just like cash its not fundamentally secure, if I leave a wallet full of cash on the seat of my car its likely my car will be broken into and my wallet stolen, if I leave a wallet full of bitcoin on an insecure device its likely it will be hacked and stolen.
This is why card cards can charge the fees they can. You pay them through fees for the extra safety they offer of being able to cancel transactions which if you made with cash the cash would gone. There is nothing that stops a credit card company offering the same service using bitcoin as the currency rather than USD, Im fact you probably will se that in a few years.
B) bitcoin goes up and down in value
Right now bitcoin is new, and we dont know if it will be the crypto currency that survives in the long term. However in the long run a deflationary currency like bitcoin will always outperform holding money as cash, as the value of USD drops consistently year by year as more is created by the financial system. Bitcoin is not a stock, it doesnt add value and pay a dividend like a company would. If anything its like gold, its value goes up as other currencies go down in value over the long run.
C) the infrastructure around bitcoin is not mature
Right now owning bitcoin is harder than owning cash or a credit card. Crypto currency is only going mainstream now and its going to get a lot easier to use in the new few years as the financial services industry adds more products on top of it. Already this year for the first time people who use investment banking services can open a bitcoin account, in a year or so most investment funds will own at least bitcoin. The mature products and services you are looking to use are on their way, but by the time they are here the chance to own a whole bitcoin for the average consumer will have long gone.
A. I can leave my cash in my house and wake up in 5 days and not worry that my USD is worthless. Bitcoin could crash at anytime, or it could go up thousands more. The point is we don't know. If we're comparing it to a cash currency it should be as stable as a cash currency, not in a bubble. Plus you're kind of missing the point, cash is tangible. Bitcoin is not, if I lose anything on the internet, I should be able to get it back.
B. Who is to say that though? I get it's a program that someone made, but who is to say it is a currency? You can look at other altcoins like dogecoin and see they're almost worthless because there is no cap, but the thing is, it's all fake. Nothing is to say this is worth more or less except for people's feelings towards it. I think the article I quoted in my first post says it best ""There's certainly a lot of bullishness about bitcoin and cryptocurrency, and that's the case with bubbles in general. The psychology of bubbles fuels it. You just become more convinced that it's going to work. And the higher the price goes, the more convinced you become that you're right. But it's not going up because it's going to work. It's going up because of speculation." In other words, bitcoins upward momentum even the price more than doubling within 90 days may be a kind of self-fulfilling pipe dream."
In reality Bitcoin is only worth what you think it's worth and same goes with any cryptocurrency. They could all fail at any given time. This is a new technology.
Also everyone likes to point out the USD and the mint printing more and more each year, but no one takes into effect how much the government destroys each year. Here's a nice article on that:
https://www.theatlantic.com/business/archive/2011/04/the-destruction-of-money-who-does-it-why-when-and-how/236990/ but in case you don't want to click the link - Think about money being created. A furiously spinning printing press might come to mind. Now imagine money being destroyed. Do you think of a three-story shredder, a bonfire, a wide blue recycling bin?
You might have noticed that it's pretty hard to find any cash printed much earlier than the 1990s in circulation. Just as more money is constantly being created, it's also constantly being destroyed. Who are the destroyers of money, and how do they do it?
In 2010, 2.6 billion $1 bills were destroyed. ( keep in mind that was only $1 dollar bills, not $5's, $10's, $20's, $50's and even $100's which also get destroyed )
So yes there is inflation with USD but there's also the government behind it keeping inflation down by destroying old money, something else that won't happen in Bitcoin. There is no one really behind it anymore keeping it anything more than a fun hobby because you very well could lose everything you have invested in it.
C. I highly doubt that most places will start taking Bitcoin for many reasons, if I owned a business the only way I'd dream of taking Bitcoin if I could quickly turn it into USD ( so my money would be safe and secure ) not in something that's fake. I read through a lot of these forums and most people are always talking about whether they should hodl their bitcoins or sell them to realize their profit. If bitcoin was a currency, there would be no need to sell to realize a profit. You already have your profit. Why sell? I don't go around trying to sell my USD for a profit, I use it to buy groceries, houses, etc... look around the forums and see how many people talk about the money they've made by investing in bitcoin. Not that the money was bitcoin.
Plus, there are only a handful of people that own a majority of bitcoins, early adopters and people like the Winklevoss twins. Most people own no bitcoin, and most people that do own very very little. The amount of people that believe in bitcoin on a mass scale is actually really low. Too many if's about the technology and I see nothing amazing about the blockchain, and how only 21 million coins will ever be produced. I don't see how that could ever stop inflation. If anything I think it could help fuel it, think about my Venezuelan example up there how 1 USD used to be under 2,000 BsF and now it's over 16k BsF... think in 200 years if Bitcoin is the only currency ( lol ) and it's split up among so many people that for a loaf of bread it costs 100 Satoshi, a gallon of milk 250 Satoshi... and they're making no more of it, the blockchain is done. People will get sick of that and a new technology will emerge saying you can now buy a loaf of bread for 1 Shanaynay because this blockchain technology is new. Keep in mind that all these new technology's are using the same blockchain technology as well. I don't get how or why that's important to it. I guess Satoshi wanted the people to feel like they were doing something productive by "mining"
I just see too many down sides to Bitcoin and too many upsides to government controlled money... and trust me, I'll be the first one to tell you I'm not a fan of the government and/or taxes, but I see more potential in it than I do in bitcoin... plus at the end of the day it's a lot easier to use by far.