It’s a simple answer but it’s still completely wrong
As others have said, it’s hard to actually compare PvP players to PvE players as they largely work different enough in both forms of content.
I’m not the greatest at either but playing raids and M+ is so different from Arena and BGs (and Arenas and BGs basically being 2 different games).
Ultimately PvP is harder to play but generally from my experience mistakes only matter if the enemy is able to capitalize on it, whereas in PvE a mistake can often times wipe the entire group. On the flip side, I’d argue the vast majority of classes in the game are very easy to play in PvE vs PvP as in PvE you generally just have to follow 1 or 2 rotations and you’re fine, whereas in PvP you pretty much have to adapt your rotation and abilities on the fly in response to what other players are doing.