Am sure people that think bitcoin price is already high right now, and they not investing, then am sure they will end up regretting at the end. If you are having money which you won’t be using for now, then I will recommend you do some research about bitcoin, and leave some money there, I will say bitcoin price is not so high yet, I can’t just image the price which we going to be seeing bitcoin price in the next 10-20 years.
It depends. People who don't invest in bitcoin now will likely regret it in 10 years if they remain poor and haven't found a better way to make money. On the contrary, those who do not invest in bitcoin right now but they have their own path, and become successful and rich. They will not regret skipping bitcoin. Like Warren Buffett or Gate, they refuse to invest in bitcoin but I don't think they will regret it.
People like Buffett or Gate are rich already. Even if they die, their next generation would still be wealthy. They can buy bitcoin anytime they want and accumulate even faster compared to people who just buys regularly.
10 years is equivalent of 2 bitcoin halvings and 2 bull cycle so people still being skeptic in buying bitcoin now will really regret what they will witness how bitcoin can still climb up.