The main key on here is that you should really be that investing on the amount on which you can afford to lose on which this has been always the main principle on the moment that you will be making an investment on which proper planning and risks management.
when you're talking about proper planning and risk management, it's not to suggest that you're investing with an amount you're able to loose but deals with being calculative enough to make provision for a portion that's going to allow you continue holding your asset without getting tempted to sell half way. The phrase
what you can afford to loose is a gambling phrase that is mostly used to tell gamblers not to go too extreme with the amount they use in gambling. For Bitcoin, for as much as we know, we've not seen it as an asset that can ever go to zero as much as we have seen it grow and so it's somehow improper to use such phrase in this kind of scenario.
I consider the idea/suggestion of investing no more than you can afford to lose to also apply to investing.. not just trading and/or gambling and maybe it applies more with volatile assets like bitcoin, even though the reality is that there is no sure investment - even though some investments are more volatile and/or risky than others.
And, sure are characterizing bitcoin as something that is more of a stable investment - and surely that seems to increasingly be the situation with bitcoin, even though there continues to be risk with bitcoin, including but not limited to the risk of it going to zero.
But I think pretty much the only threat that could drive bitcoin to zero is when there is some technological mess or advancement that makes bitcoin redundant or useless because there is something better than it. Otherwise I understand there can be unforeseen developments, but what else could there be in the near future with a similar or stronger security architecture and predictability? A fixed mathematical schedule for emission and the security through redundancy in the nodes globally distributed and holding the data, it seems to me that there can't be much that is better overall.
The solution to the SPOF problematic is so unique that I don't see how this could be done with a higher level of security.
The biggest problem still are the fees at times for people who do it right and want to manage their own wallets instead of buying it and leaving it on an exchange or as some derivative from some corporation dealing with bitcoin (ETFs for instance). For small investors it is still a hassle, but I doubt that the fee problem will be solved to a degree in the near future where people with small budgets can reliably follow a DCA plan. Then again I doubt that there will never be a solution.
There is also lots of dilution from many of the shit coins. Bitcoin represents about half of the total crypto market cap, but their hope is to hit the so called bitcoin killer. But I get that smaller investors would like to get into the market, but then realize that their $100 DCA investment every two weeks is sometimes stuck because it costs $20 to get the money off the exchange. A simple layer is required that may not offer the same level of security, but still allows small investors to move their bitcoin. The lightning network still sounds too complicated for the vast majority to be used, it scares them away and I get the point. By now you have all these gamified apps that allow you to trade everything and since it is simple, they tend to prefer those apps and trade there.
And sometimes I think the mystic around Nakamoto can be interesting to some investors on the one hand, but scary to others on the other hand as they fear there could be some ill intentions on behalf of the founder, like it comes to light that some rogue state brought bitcoin to life and does hold the majority of the coins. It's not that I am afraid of it, but it could be an explanation for some people to stay away since they rather have a figure they can see and assess. Take Elon Musk as an example or Steve Jobs: whether you like them or not, but those who do feel more comfortable when they actually can see what someone is doing and how they are behaving.
After all, bitcoin is a very different investment compared to owning shares in a company that has a cashflow and a financial report. The good thing is there is no blowing up of bitcoin because someone faked financial data, like there was with some big financial corporations or any of the accounting scandals. It is all mathematical and hence the happenings within the network are clearly predictable (I mean the hard data, not things like price manipulation). In a corporation you can't tell what someone might do next, It is an aspect I like a lot about bitcoin and that is why I am confident it won't go to zero as it will still have value for various groups of people. Value preservation, highest mobility of any asset in the world and autarchy if someone does it correctly.