I knew Bitcoin as legal tender wouldn’t work long term because most people don’t know how to use it. This is similar to people paying their debt in Pennies to piss off the impound yard or ticket agencies. But they have to take it since legal tender means a debt owed.
Making bitcoin legal tender I assume was more for publicity than actually solving any issues. And I wonder how many actual debts got paid by bitcoin, probably not many.
Your point is the correct but not every work is learned in advance but one has to work hard in it and one has to know about it. Similarly, we did not know about its development and success but now it has improved a lot so many of us have started knowing about it. And there will come a time when it will become common all over the world. If it had been successful then it would have been a problem for some time because not everyone has money to invest in it.
If that had happened, who knows, the price of Bitcoin would have plummeted and everyone would have suffered huge losses. That's for those who have worked in it and are investing money in it.