I think this guy should stop regretting. He used to do astrophysics and there were things he didn't like about that. He's now doing data science and there are things he doesn't like about this, and looking back (with a bit of rose tinted glasses) at his life 7 years ago, he has regrets.

Newsflash: the vast majority of jobs out there are not that fun. That's why you get paid. If they were a lot of fun, you'd be the one who pays, just like you pay when you go to a concert. Some jobs are meaningful. Working for Moderna and making a vaccine that's going to save millions of lives, that's meaningful. Finding a cure for a certain type of cancer, it's meaningful. But saying that astrophysics is meaningful because some internet surveys find it to be "the sexiest job in the world", that's quite shallow. 99.9999% of the jobs out there don't end up with you saving the world. You just do some stuff, get paid for it, and then go home and live your life with your family and friends.