Interesting question, I know. For me personally the answer is no - I have not ever regretted having gotten into bitcoin, despite having spent hundreds and hundreds of hours researching the topic.  It's always been an interesting ride.

But I have a friend who got scammed and he regrets having had anything to do with crypto in the first place. It's pretty sad but there's nothing I can do about it. I even offered giving him half of the amount he lost from my own crypto stash (mind you I am not rich) but he's so scared that he's not interested any longer...

This and other questions are part of a questionnaire that we, a research team from the University Institute of Lisbon (ISCTE-IUL) are doing. It seeks to understand the drivers' usage of cryptocurrencies by the end user such as you and me. Considering 10 different dimensions, from perceived usefulness to privacy to profitability, among others.
It takes on average 3 minutes to answer.

Here is the link for the questionnaire: https://www.surveymonkey.com/r/cryptocurrencies_usage

More details if you want to know more about it:
For this, it was created a questionnaire with Likert type scale questions. These dimensions will then be used to construct a model, based on the traditional Technology Acceptance Model (TAM) developed in 1989, and some others developed afterwards, but with more adapted to the cryptocurrencies ecosystem. Then it will be done some data analysis and compilation of results.
This questionnaire has some focus on the financial area, but this does not mean it is the most important. We know there are some other dimensions not being addresses in this questionnaire, such as decentralisation/government influence, that may be addressed in the future.
After analysing and publishing the thesis and papers I will post on this forum with infographics and the most important conclusions of the study.

There are no open questions, but you can post here or message me about this.

Thank you for your time! Best Regards,
The University Institute of Lisbon research team

Every time have you start for joining and participated at investment of crypto currency is always correct time, you can joined every time you want because is always correct and the best time, you can take profit with buying lower price of altcoin and sell it at higher price.

From what I have seen so far in this forum and other crypto platforms, most of us want fiat eliminated. But let us not forget that there are still situations whereby we can't use crypto except fiat like in rural places without computers or even internet facilities.

How sweet could it be?

I really want the professionals to shed more light on this if it could be actualized and how easier could it be and what implication can it have on bitcoin

You can store your cryptocurrency coins on a cold wallet or on a paper wallet, so you will protect yourself 100%. These are the most reliable ways to store cryptocurrency today.