For the lay person:
It’s like if you could see Twitter threads and Reddit posts on your Facebook in a single feed, and choose between them which set of rules, interfaces, and styles you prefer. Since everything shares content, it is easier for new sites to open which helps keep the user experience competitive.
Some suggestions, either online or local;
Bookclubs
Walking groups
Chess, board games, table top
Theater groups (meetup groups to go to the theater as a group)
Escape room group meetups.
Depending on if you are in a city or a smaller town the locals options will vary. I’d look at meetups site and browse local activities. For most any activity you will find a range of ages, but some will skew more one way than another.
Best of luck!