I agree. Engaging in hobbies and activities that bring you into contact with other people is a great way to make new friends at any age.

I recently started playing at open mics once a month with a couple of guys (one who is 10 years younger and one who is 20 years younger) for fun. And it happened because I asked someone to do it with me. The third guy asked if he could join us. It takes effort and a little “putting yourself out there.” We have become good friends. Plus we have met a lot of new people at the open mics. And some of them are becoming friends.

You have to get out of the house (or invite people over.)