I prefer a game that has a lengthy, but fun grind, and one that is challenging. By challenging, I mean that there is content to do at most levels where there is a fair chance at failure unless the player is seasoned. I also enjoy the slower leveling from a game like Wow classic, original Aion, or pushing 100 SSF style in PoE.
About 4 months ago I tried out New World, and it was entirely too easy to get to level cap, and there was little challenge the entire game PvE wise other than M3s or the raid, which was quite disappointing. (Yes, it is by and large marketed as a PvP game, although there wasn't much of it in the open world and I did go to the PvP zone often.)
I am a bit cautious about diving into an MMO, because unlike other games, it can take quite some time to realize the direction the game will end up.
Also, by challenging I do not mean intentionally gimping oneself or doing content that is way above level to create a challenge.