Give me 100 rubles, and I’ll make you a king!

Here, you need to upgrade weapons or other character equipment, or maybe you want to craft something top-tier. You can, of course, farm the necessary resources yourself, but what someone achieves in a year of daily dungeon runs, another can do in a couple of days just by going to the terminal. And it's not even about the rarity of anything, but simply about the quantity.

It needs to be the case that someone farms it first and then sells it. In the end, the best items are still with those who obtain them independently, and not with those who buy them afterward. Although those who buy also get their benefits, especially in conditions of an abundance of resources on the market.
PvP is a bad example for discussing donations. It's a Korean game, and its target audience is willing to spend 24/7/365/80 in the game. For them, it's not a problem not to donate.