Ok I guess i'll check one of those communities on PS4 then, thanks. I've looked in those before and they seemed a bit dead.
Not sure why you're surprised when you're listing methods outside of the game itself.
Yeah on PC it's a bit more outside the box, I agree. But if a game is on Steam, it's almost the same, I think the game forum that you open with your keyboard combination has a group area as well, but if it's somewhere else like on Epic, I don't know 🤔. Here in Germany, Facebook (looking for) groups are also a big thing for games, specially console games, there are big ones for every game and you can find people there all the time, don't know how this part in US is tho.
You're on PS4, that's great in that regard, not as good and easy as on Xbox One, but almost. If a group is set correctly you could directly join party chats which got specifically opened in this group, or via PlayStation group app on your phone, group message such a party directly, or the more classic way, look into the text field what the newest messages are and answer one that seem to fit. Easy. (Or create a message for yourself of course with what you need like "Level 100+, age 18 and up" or whatever)
You can also use the phone app for that which makes this a lot easier then navigating through it on the console. Use that all the time when I try to find people for Dead by Daylight.
It's mostly a great and super fast experience and playing with randoms is completely unnecessary thanks to these functions. :)
Good luck.