While innovation is very important, I think that there is an unhealthy obsession with it. That obsession has a great deal of harmful effects and is a part of why people are increasingly holding tech in a dim light. The extreme focus on innovation leads to companies being abusive. Being abusive is a thing that has become normalized in the tech industry.

Do the big companies really use and develop the acquired technology though? It seems like most acquisitions end up being shut down and/or crappified within a few years.

Sometimes they do, sometimes they just buy companies to eliminate competition or future competition. Sometimes it's some of A, some of B. It really depends.