I think it's essential to have some mental strength to resist any FOMO that comes with a live-service game. Personally, I try to solve that by sticking to my targets. For example, I don't do daily quests just for the sake of the daily quests. Sometimes I do them just on one character, sometimes on more, because the actual rewards can drop a currency that allows for housing item purchases. I log in to check what items I sold with traders and for how much, and then put new items on sale, because, for example, I want to gain some sum of money to buy an expensive in-game item, house, etc. Or, say, there is an event going on. I only participate in it and define for how much time if the event is actually fun for me. If there is an ongoing event, but I'm interested in building this or that character, getting a difficult set for them, or upgrading their skills, I prioritize my own tasks, not the event.
I still like ESO for both the world and stories, and the MMO part. It's fun to, one day, complete a Thieves Guild story and learn the personalities of 5 interesting NPCs involved, and then, the next day, play BattleGrounds and get acquainted with a few other good PvP players.
I can see how RL can interfere, and that's totally fine. RL is better anyway (at least it should, right?)
Sorry to hear about those issues in Guild Wars 2. They sound a bit too much. With all the issues ESO has, I've never experienced anything like that when an expansion/zone launches. Hopefully, Guild Wars 2 devs learn from this situation and approach new content releases with more quality.
P.S. One note about ESO: going forward, they are actually decreasing the FOMO, removing daily endeavors, and giving a lot of in-game options to get crown-store limited items previously. This is not meant to persuade Cahir; I get his family/gaming priority situation, but just FYI.