Almost any online service has plenty of competition, but it doesn't prevent enshittification once one of them proves that you can squeeze more revenue out of users and get away with it. Netflix charges you the same as five years ago, but you now get ads. You pay for Amazon Prime and get ads. You pay for Spotify, but they now serve you AI music from fake bands to avoid paying royalties to humans. The end game is that all consumer LLMs have ads in the free / cheap tier.

And as other folks are saying, the whole point is that it's a different type of an ad: it's not an annoying pop-up or an unskippable video. It's a subtle recommendation that you don't even notice. High conversion rates, little fatigue... getter than all the cool characters smoking in films a while back.