I agree this is a result of monopolization or more specifically "lock-in." I spent some time at Microsoft making products in their 365 suite and it was frankly known that enterprise contracts with us were a form of lock-in--the idea of moving a 100K employee workforce off of Microsoft 365 and onto something else is nearly impossible. So management didn't worry much about quality.
Enshitification follows becoming a monopoly or a cartel.
For example, how is any scrappy, quality focused startup going to unseat Google, Amazon, Facebook, etc? Even Apple seems to be heading down that path.
I agree this is a result of monopolization or more specifically "lock-in." I spent some time at Microsoft making products in their 365 suite and it was frankly known that enterprise contracts with us were a form of lock-in--the idea of moving a 100K employee workforce off of Microsoft 365 and onto something else is nearly impossible. So management didn't worry much about quality.