After putting in quite a few hours into the game I was starting to wonder why loot never really changed. I kept getting loot as rewards for doing things and there are plenty of other means of getting it, but 35 hours in I still felt like I was basically as strong as I was 5 hours in.
So then I went to check their forums and the concensus seem to be that the game isn't a loot-driven game. There is loot, but it doesn't really matter. Supposedly it's trying to be more of a standard FPS and keep a balanced pvp environment. I didn't dig deep enough to find any confimation about this from an official source, but it was a very apparent sentiment from people who had been following the game for a long time.
Now while that's fine and all and there's nothing wrong with a game that doesn't overplay the loot-role, but it's a problem when they are not just selling you access to more loot for real money, but also random loot. Buying loot-boxes in this game is basically just giving away your money, it doesn't give you any advantage in-game or anything fancy and shiny to look at. It's also one of the only things in the game that is visibly pushed as a microtransaction and all it is is a random chance at insignificance.
So ye, don't buy loot in this game. And, as already implied, if you were interested in this game for it's loot hook, stay away.