You probably need to figure out what do you want. There is nothing wrong to be alone, not have family or kids. Unless it bothers you. There is nothing wrong to rent a home. Unless it bothers you. Figure out what you want, how the future in which you want to leave looks like. If you can’t, maybe talking to a psychologist worth a try - decide what problem you are trying to solve, book a few sessions, see if that moves you towards your better self.

Financially, I agree with many on this thread - keeping all $100k on a savings account is one of the worst things to do with your money. Keep a couple of months of expenses on savings, put the rest to work. CDs are mostly safe, and help offset the inflation. Buying home isn’t a bad option, and if it’s just a place for you to live, don’t consider it an investment depends on location, but you’ll likely save on monthly payments vs rent.

Once you figure out what you want from your life, talk to a financial advisor to set realistic financial goals and decide on home purchase or investments.

We know nothing about someone’s situation. If his father put all his savings into real estate instead of a retirement account, maybe he needs it to cover the living expenses. And we know almost nothing about their relationships.

It’s easy to tell someone what should they do… If it would be me and my son, I’d probably swapped one of the houses to get him a condo to live in. Charge him fair rent, or maybe not, but at least he wouldn’t be at mercy of some random landlord. Sense of stability is empowering.