This is all due to having a device in your pocket constantly connected to the sum of all human knowledge. This device created an attention economy that forces producers/developers to create ever increasing ways of engaging your attention for as long as possible. Mobile game spend was $80 billion in 2020, PC $37 billion, and consoles $45 billion [1]. There are still games out there that don't go the loot box route, but perhaps they aren't as popular (addictive) as the free loot box ones, specifically due to the reason mentioned in the parentheses.

[1] : https://www.washingtonpost.com/video-games/2021/05/27/mobile...