Actually, there weren't as many problems with those two games removing the trinity as you think. What they did really was no different than FFXIV where players could pick and choose abilities that made them fit a tank/dps/support role. FFXIV just makes it much more obvious it's a completely different job/role/playstyle compared to those two games. It was the other problems that caused a mass exodus and made the game feel like a desert.
The biggest problem for ESO was that the Elder Scroll game fans wanted an Elder Scrolls game and got an mmo inspired by Elder Scrolls. Players didn't leave ESO because they disliked the system, but that they wanted to customize the game more than what the devs could and that Skyrim offered everything they wanted (especially once player created content copied elements from ESO).
GW2 simply has an atrocious economy. Part of it was due to their innovative counter to RMT by becoming the gold traders themselves to monetize their development, but it backfired on them and drove in game prices and real world prices through the roof. Couple that with the horizontal progression and a lot of players just stopped playing as much once they got through the story and got their gear.