Yep, they will regret for sure, the same way that i regret for not getting into crypto a couple years ago when i first hears about it. Blockchain technology will go mainstream as it's a great technology, and we will see a great bull run when it happens.
Indeed most people in the world still aren't aware of cryptocurrencies, and most of them feel that way. I also regret that I didn't invest in cryptocurrencies in the crypto market last year, so I didn't get anything.