This. Worked at HP for years. It was a pretty great company for the most part.
Until Carly Fiorina joined. Amazing how one person can so transform a company - in a bad way. It started almost immediately. But buying Compaq really accelerated it. Companies like Compaq that have been in a slow death spiral throw off good employees.
That leaves low performing politically focused who protect their own. When they get purchased and “integrated” and they start filtering throughout the parent - like an infection, spreading their poison and killing it from the inside out.
HP was on a downward trajectory before that. Which is why Fiorina ended up on board. As a colleague of mine notes at the time "Bring back Lew Platt" was not really a strategy either. I do think the big computer companies of the era reached a certain ceiling beyond which it was challenging to grow.
Haha this prompted a flashback to an all-hands we had when purchased by Lucent, led by Fiorina and her minion Lance Boxer (you might think that's from a comic book, but literally that was his name... for when the pugilistic becomes pornographic). She talked about how we were all in for the long haul together, and was gone to HP within months...
Certainly a 100,000 person company is going to have characteristics that someone who generally prefers a 1,000 or 100 person company may not much like. But not all large companies become "terrible" companies--whatever that means exactly.
As the peer comment notes, there are also companies that remain private and mostly small and march to their own drummer. Of course, those can easily end up in family control spats and the like.
Nothing's perfect but I'm not sure the lesson is everything sucks or dies in the end.