What happened to MMO's?

They are still here/there :) Me personally i just grew out of them + they are huge time suckers i just dont it as much as i used to .

Have you tried older MMORPGs then? Some of them are still alive (and hopefully not badly revamped), might have an more adult community and those game mechanics as you described. Haven't played any since my last trial to get used to SWTOR a few years ago, so I can't recommend you anything.

MMO is not the same as MMORPG.

From what I can tell, Path of Exile, SWTOR and Mabinogi (all F2P btw) seem to have active communities depending on what server you're on. I play entirely solo; however, I suggest that you try whichever MMO interests you and get involved with the games' guiilds/clans if you like the social co-op aspect. They are always recruiting.

EDIT: I suggested these... not because I play them, but they have been around for a considerable amount of time and have decent end-game content. Additionally, they have a good content balance for solo players (like me) and for playing with large groups.

Any example of such MMOs? I've never really had the chance to play anything like this (and I guess that's a good thing since I'm a MMO soloist in most cases).

http://store.steampowered.com/app/552110/Puzzle_Pirates_Dark_Seas/

Simple answer? MMO part doesn't fascinate people anymore and everything online these days has some form of, usually persistent, progression.

Those games are dead. Under my experience, people who keep playing like that are very into it... very very very into it and has a strict schedule for raids. Apparently only some guilds on wow and (maybe?) FF14 is like that.

Some MMOs (including wow) took the casual way, more players means more revenue, more easy content means more feeling of acomplish or pride (not EA style), that means happy kids and a kid happy with the game is a kid playing it.

Some other games took a sandbox spin, more relaxed but super grindy, or at least is what I read about black desert and GW2 in high levels is stupidly grindy too.

MMO formula is dead and now is not that appealing anymore.

Dungeons and Dragons Online is very team oriented, and many of the puzzles and fights require cooperation to finish. It's been a while since I played, but I remember the quests being pretty fun and not just the generic grind that's common in many MMO's. The graphics are a bit dated now. It's free to play, but many of the quests are DLC.

Recently I steped on Secret World. I couldn't play it before because it was locked for my region. MMO where you can start and don't look for overpowered items at least for full (HUGE) main quest line and standart dungeons. Lots of humor, proper accents in dialogs, lots of detective missions - i.e. there are tons of quest that does not include "kill/bring X mobs/items"
And devs still update it very often.
As for gear, you buy green stuff on auction and just level it to legendary rarity.

You can still find classic MMOs out there, but tastes have changed a bit over the years. People drifted from MMOs towards MOBAs and Diablo style action RPGs. Stuff that's easier to pick up and play.

Vanilla WoW is coming back at some point. Depending on how they implement it, it might be nice.

Mobas took over. And now Battle Royale games are infringing on their turf.
.
As a genre they aren't dead though. Once invented, gaming genres in general go niche, but they don't go extinct.

Well my most beloved one, Crimecraft died, so...

What you are looking for is available here: https://www.project1999.com/

Tree of Savior was fun for me.
They dont have a very big community though, but I found it fun.

check this out
https://chroniclesofelyria.com/

They suck

I still have one MMO that over the last decade have spent over $2k on... it sounds stupid looking back but I did enjoy the game with friends. It was basically chat/msn/discord but in a game.

Name a single MMORPG that actually has ever fit in with the ideal you've presented.

Perhaps Project Gorgon might be up your alley.
https://projectgorgon.com/
It's a huge time/gold sink to learn everything, so players specialize and work together. It's in an open testing phase, but will be B2P on Steam eventually.

I remember how Dark Age of Camelot has been shut down by the publisher who wanted to push his new MMO. I don't even remember what it was, just that it failed totally. Part of the community I was in went to WoW, others like me stopped playing MMOs :) I don't regret it, but I would be happy to get back to DAoC for a few hours.

There's Dream of Mirror, if you don't mind the slightly goofy looking cel shaded graphics.
http://store.steampowered.com/app/335820/Dream_Of_Mirror_Online/

For real, Puzzle Pirates: Dark Seas is fun as hell. I'm back in babyyyyyy.