As many years as I put into EQ1, I started mid-velious and didn't find it all that engaging. I definitely preferred the post-Luclin era, which had more incentives to group up for experience, started really differentiating the classes (like making the ranger's archery actually viable for damage output), and overall improved the experience. In terms of gameplay, this improved further with additional AAs in later expansions. Sure, the lore was all over the place, but honestly I don't mind that kind of schizo take to story telling, I'm sure it saves a lot of effort from not having to tie things together or retcon old lore.
Of course, Luclin was kind of a low point content-wise, especially in terms of raids (lots of health sponge fights), and GoD wasn't much better. AoW improved on that in terms of raiding, and LDoN helped with pre-raid content. (Let's just forget about the clusterf* that was PoP flagging. GoD/AoW had some too but to a much simpler degree, and could be simplified further.)
What kind of killed the experience was the instancing. But I'm of two minds about that. Obviously, it reduces the socialization aspect when you can just dive a dungeon with friends and not cross paths with anyone else. On the other hand, it really sucks to plan a group or a raid (and raids were a huge personal investment, can you imagine taking 72 people into a raid in World of Warcraft? What a mess that would be, I don't think battlegrounds even get that large) only for the content that you can kill and still get useful stuff from to already be dead. Sure, that promotes competition and socialization but sucks for people with real world obligations.
I really think LDoN was a step in the right direction in terms of broadening the mid-game/pre-raid experience, it is just that the instancing sanitized the world. If there was some compromise between LDoN's dungeon rewards without the instancing, it would help immensely I think.
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All that to say, no, I wouldn't go back to EQ99, even if I had the time to dedicate to an MMO right now. I considered one of the other revival projects, but never actually got into it. I don't even remember what it was called, but it was spiritual in nature and not a direct revival, having redone zone connections and changed the world and lore.