Because you need to play rated PvP ( arenas and rated battlegrounds ) to get better gear than 200 ilevel .
Just spamming unrated PvP only gets you to 197 and after a while 200 . And that’s a hard stop there. In BFA you could just do unrated and get upto heroic level gear which is what is the 213 gear in SL after many weeks of playing and stacking up CQ points. However they removed that in SL which is a sore point for the unrated crowd.
I’m not going to get into measuring the “skill” required to do things, but the following are things that some people actually do lack the skill to do.
After you get to around 200 item level (it can go a bit higher with legendary, world boss drops and 203s from callings), you only have three paths of gear progression. All of the following require some degree of “skill” unless getting a carry from other players.
Raids
Mythic+ Dungeons
Rated PvP
I was saying that just playing a lot isn’t going to get you better gear in these formats. For example, there are people below 1400 rating (required for 207 gear) with THOUSANDS of matches played.