The main problem is that if the company's model is "growth and engagement", the objective of the company is for you to "engage" with them (and look at the ads or whatever dark pattern they're pushing). It is not to help you accomplish whatever task you were trying to do with their product. The "product", if it's there, is merely a necessary evil to convince the users to "engage" with it.

The PM couldn't care less about whether it interrupts your flow - he just knows that interrupting the flow of millions of people will net them that next promotion and a nice "increased engagement by double-digit percentages" bullet point on the resume. The company executives don't care either, because they know that boasting about the increased engagement figures will make their stock price go up.

By the time the degraded experience causes actual repercussions for the company (if it ever does - it won't if they've got a monopoly), both the aforementioned PM and executives will be long gone and will already have cashed out.