I personally think direct micro payments for skins, even without randomness and lootboxes, are still problematic. They aren't as bad as lootboxes, which are clearly designed to extract money, but their problem is that the potentially limitless money you can spend. If you go into a game knowing that it costs $60, you know that's how much you're spending on it. If you go into a game that hands out skins for $2.50 a piece, there's no limit, and unless you're good at making and sticking to a budget (which is a large portion of the world, especially kids who have no experience!) you can just as likely spend way more than $60.

This is worse when such things as skins end up getting tied to status within the game world. Fortnite doesn't have randomized loot boxes anymore, but that hasn't stopped kids from spending tons on V-bucks, especially since they get bullied if they don't [1]. Seriously, just look at videos of people bullying "defaults" on Fortnite. I think it's especially bad because there is a way to finance long-running multiplayer games: battle passes. It's an upfront cost so you always know what you're getting into.

1: https://www.polygon.com/2019/5/7/18534431/fortnite-rare-defa...