I have only played Fortnite Battle Royale (like most Epic users I guess), but there are no loot boxes involved, and it feels very different from freemium mobile games. You pay for skins, or you pay for challenges that make the game more interesting, and for which more skins are the reward. That's it. And you can't wear more than one skin at any time, so it doesn't really encourage binge spending.

It's so harmless that even the non-monetary "engagement hacking" by other services feels like a burden in comparison (e.g. Steam's incessant notifications about new crappy stickers - stop stealing my precious time!).