The basic lore is basically this is some lost continent that used to have some type of ancient, powerful civilization on it. There is some resource called Azoth that functionally makes everything immortal/undead. So you've got Conquistador shit, but then you've also got Colonial times outfits as well. The premise essentially lets them dump whatever time period they want into the game and explain it away as "they visited the island at some point and the island is essentially time lost". Like the next zone is going to have Ancient Romans and Ancient Egyptians that had previously visited the island.
The core gameplay is pretty good - action combat limited to 3 abilities (that you can swap out of combat) and skill trees. Armor load will impact your ability to dodge or have other buffs/debuffs. Like light armor is super mobile, but you've got like no mitigation. If you're a god with using iframes to avoid damage, or kite people, you get the advantage of a big damage and healing buff from light. Heavy you can't dodge for shit for the most part, but you can be quite tanky with the right loadout (although they recently added a -30% healing debuff if you are in heavy to avoid the tankadin builds that were essentially immortal). It is also varied enough that people keep discovering new metas, although balance usually makes certain metas overall better. Like the Schizo meta (sword&shield + blunderbuss) or S+S&Hatchet is a really powerful stunlock build you can do - basically think stunlock rogue from vanilla WoW. It's cheap as fuck in 1v1, but in group combat it isn't so hot. You essentially have to blow your entire cooldown load on a single target. So in wars all it is really good for is trying to murder backline healers before anyone notices you.
The bones of the game are actually really good. Where they failed is they listened to the "Vanilla EQ1 was the best MMO ever!!!!1!!!" crowd and decided that 20 year old game mechanics that no one likes anymore were a good idea. Long grinds, punishing deaths, needing to fucking run everywhere. They also leaned too hard into giving players a lot of agency in towns - you essentially have guilds using towns as their personal piggybank to line their own pockets, while only marginally managing the town. This has also caused massive inflation in item prices. Like the gold cap for a player is 500k, and people sell shit for more all the time.
They've taken a lot of actions to roll back or soften some of the dumb ideas (like dungeon orbs), but they will need to invest a lot more in the game before people come back. Their recent actions have somewhat stabilized the game - the player bleed isn't as pronounced as it was. But they have a really long climb ahead of them to even get a decent fraction of what they used to have back.