50 years old without any savings, god daym, this story is sad as fuck.
Sure it is sad, but you can also read some of the details that bones provides to show that he has chosen some of his situation.
You should have invested in the stock markets at least dude. I missed the crypto train mostly too, since it was a whole new concept and was a risky investment but people who took that risk made the millions not those who didn't.
No matter what your monthly salary is, you should keep some of it and invest in different assets. (used to be stocks, cash, gold... now it is crypto, cash(should be your smallest investment), gold and stocks-this one is in a bubble right now probably, wait for the crash) Saving $100 or $200 per month might not look like a lot at the first glance but after 20 years, it may grow into a lambo or a house at least.
I think that you are right that investing a certain amount of money every month (or every week, depending on how you plan your budget) is a way to build the long term... that saved money can be $5 a week or even a smaller amount, and it should be set aside only after you have established an emergency fund and you have also gotten into the practice of making sure that all of your expenses are covered, such as not living off of your credit cards (that is spending more than you take in).
A problem with a lot of folks is they start to believe that the amount that they saved over the years, becomes a piggy bank that they can just cash out all or part at any time or to take profits too quickly and too much.
So, living within your means, and not getting tempted by spending the amount that you have saved can be very prudent mindsets. You are correct that it should not matter how much you make in order to attempt to stock away a small portion of what you make... and if you are having to draw into your savings, then either you have to cut back on your spending or figure out a way to earn more to cover all of your expenses.
Let's say that over the years, you have built up $10k into your investment savings, and then yes you might be able to move some of those funds around. Of course, if you have a 401k, you might not be able to easily move those funds around, but there should be no reason to cash out of your 401k unless you are really sure that you can make up for the penalty that you are charged by withdrawing it. But even if you can move the $10k around, that does not mean that you should start to gamble with it.. so yeah some of that might go into crypto and some might go into other kinds of investments. I certainly don't recommend diversifying within crypto, unless you have established a decent bitcoin position first, and then you can branch out once you have bitcoin figured out.
Even though I made a lot of money in bitcoin, I still don't really feel any compelling need to branch out into other cryptos - even though I do happen to have a few other cryptos, but that was not really anything that I actively pursued beyond just playing around with a couple percentage points of the total value of my BTC investment.
Another point is that some people get into a mindset that they believe that they have to gamble because they are already in a bad position in order to make up for all that they lost out on... which is not a healthy mindset. The most healthy mindset is to figure out a plan that works from your current position, rather than trying to make up all the shit that you screwed up in the past. So if you have various expenses to cut, then you can do it, and if you have various high interests credit cards then you should pay those off.. by paying the higher interest ones off first.. and chipping away and chipping away to build and diversify your various investments while making sure that you living expenses are covered, and even establishing a cashflow plan that goes 6 to 18 months into the future, so you can see how much money that you have to spare on an ongoing basis and see that some months have tighter cashflows than other months.