Diablo Immortal isn't quite pay-to-win, but it's close

pcgamer.com:

If you're looking to pop demons and pick up some loot in Diablo Immortal(opens in new tab) for more than a few hours, you'll probably have to pay. NetEase and Blizzard's mobile-first and now PC-ported Diablo game is built to obfuscate how real money transactions can influence your character's strength, but the most dedicated players are probably going to discover its significance soon.

It's still too early to say how much Diablo Immortal's microtransaction systems will shape the endgame experience but, in my limited experience with it today and via reports from the game's beta, it's designed to monetize the grind that is at the heart of a loot-based game. It's not unique for free-to-play games, but it's the first time Blizzard's popular series could prioritize your wallet over your time.

Diablo Immortal won't immediately(opens in new tab) launch in Belgium or the Netherlands because of their laws against loot boxes. They aren't actually literal boxes; they're rifts. Like in Diablo 3, Diablo Immortal has rifts, or portals that send you to randomized dungeons filled with tough enemies and rare rewards. A critical part of the Diablo series has always taken place after hitting max level where you fight harder and harder monsters for increasingly better gear. That's why people still play the original games to this day—it's sort of the point. Diablo Immortal is the same, except now you can pay money to increase your chances to get powerful items, specifically out of its rifts.

Crests are items that modify rifts to increase (or guarantee, with Legendary Crests) the percentage chance of receiving rare gems to slot into your gear, items that will give you strong passive effects and stats to help you in the endgame PvP and PvE