Enshittification happens after the company was quick to deliver a working solution. They successfully captured the market, killed off the competition and now they are ready to start milking the customers who have no other choice.
AI slop can actually help with this, because it reduces the cost of replacing their enshittificated software.
The reason its hard to dethrone Facebook, Instagram, YouTube, Twitch, etc. Is not because it's hard to recreate the software (it may or may not be) it's because of network effects, budgets, etc.