Endgame right now is pretty much just PvP yeah. There aren’t any super hard PvE gates yet, except the elemental towers which mostly give generic rewards.
Gameplay is a bit shallow, but entertaining enough and it being real time action instead of turn based like most gacha is nice. If I had to compare it to another, it’s similar to Dragalia in gameplay depth.
For grind, it’s about what you would expect from a gook kusoge, but you can unlock a stage skip function that lets you burn all your stamina instantly, and we don’t get nearly enough stamina handouts that you can grind for hours on end in anything anyway. GT’s sidegame tier after you finish the story/ongoing events.