Everyone knows the tale of Brand X getting bought out by some faceless global conglomerate and going to shit, but does the opposite ever happen?
The context provided in the question is of big companies buying smaller companies and ruining them. OP asked if “the opposite ever happens”, which I interpret to mean a big corporation buying a smaller company and it NOT going to shit.
Sure we can talk about any change in ownership whatsoever, but that seems like a complete change in topic with an obvious answer.