WOW was good for a while but then so was EQ, DAOC and GW1 and 2.
Now, I don't play any of them at all. Well, at least not the live servers. I play WOW on my own server with really awesome bots and I stick to the first three games. EQ is another one that I only play on private servers now. GW2 I did play on live server a while back but only for a day or two.
The originally MMOs were so much better then the stuff that came 20 years after.
The main difference is the masses jumped on board. EQ was awesome because of how tight knit the communities were. Early WOW also. Then they just keep watering everything down, add bullshit the long timers had zero interest in, etc. I dropped wow at the MOP stage because it literally just felt like a second job to be raid ready. It was like a light bulb went off and I never went back.
Shooter games were better 20 years ago as well. Unreal Tournament was great. UT2004 was amazing to me. Numerous different ways to play the game. Now, the most popular game is a battle royal that feels like a fraction of a game. One fucking map...GTFO here.