I remember a startup that had a great product that would match you, a person with a questiojn about a topic, with an expert on that topic, over gChat. Google acquired them, and they immediately were told they had to port their infra into google3 and borg. This was a short window where the new hotness was help-over-chat.

They rewrote their whole system and then Google told them they didn't actually need the product (and from what I can tell, the help-over-gchat idea isn't really a product space any more). So they pivoted and made user profiles- that is, for every user at google, they inspected all the history of that user, and made a simple model that represented them. at the same time, several other groups were competing to the same thing- and a more powerful team licked the cookie and took ownership of user models at google (often, the leadership would set up various teams in competition and then "pick a winner").

After a few years, all the acquihires left google in disgust, because google had basically taken their product, killed it, forced them to pivot, and then killed their pivot.

What a shame and waste of resources.