Normal to not have many friends in mid-20s?

There is what pundits describe as a "loneliness epidemic", in the last 10 years so, so it's somewhat normal, in the sense of it happening a lot. Millenial/Gen-Z world has a lot more isolation that the past. Aside from the general bleak perspectives, one reason is that up to 80s and 90s, if you wanted some fun, you had to get out in person and make shit happen. Nowadays people spend hours on their smartphones, game setups, and social media, "communicating" but ultimately physically alone.

Hanging out with friends being less than before is also common in the mid-20 in general, as people that age don't automatically get spend time together (as is the case in high school and college), and everybody is getting busy with the rat rate. And when when you're back home from work, they're more likely to Netflix+doomscroll, exhausted from the day, than to go hang out.

As for improving the situation: try to see if you can increase the frequency you see your existing friends and make a deeper connection. You might want to see if you can propose and initate some common activities too (like some baskeball game, or travelling together somewhere, or something like that).

Try some social, in-person, hobbies, where you can meet people (from gym and rock climbing to sculpting and dance classes). Maybe try some scenes, like hacking clubs or comic book fan clubs. Put yourself out there, where there are other people also looking to connect.

Social isolation can also be a symptom of ASD. If one addition to rarely seeing friends you have some social difficulties (like being bullied at school, or not reading social situations well, feeling alien, or probems with making and keeping friends in general) you might want to explore that possibility too. ASD/HFA is more common to people in tech than in the general population.

I like to think have a lot of friends at surface level, and I used to have solidly close friends, but pretty much all of them moved to other states, so I see people in real life at about the same frequency as you. Some of them I maintain a digital friendship really well, but it is a challenge. This is a transitional period for a lot of people. COVID did not help this. I've also always been pretty introverted so my main method of making friends is "daisy chaining" off of people I already know. Like if you know one person, see if they can invite you to a get-together with other people they know, and so-on. That way you also have the added trust factor of "this person is vetted by another person I trust", instead of going in blind. If you have friends who live in other places see if you can arrange something like a digital movie night where you watch the movie at the same time. There is also online chess or online Scrabble (Lexulous is an online Scrabble clone) that you can play while chatting over the phone. My ideas might not be the best of help, but you certainly aren't the only person in your pickle.

rent a 3br apartment, sublease the other rooms

host a monthly dinner

join a meetup club for something you're interested in

remember - everybody else is lonely too, bring the party to them