Some people are great at the research / experimentation phase but not great when it comes to scaling up. Other people aren't great at scaling up but are great during the operational phase.
The operational phase is the only place profit is generated, but the other people need to get paid, too.
Instead, it will lead to the inevitable enshittification as customers are milked for more and more profit while the tech decays because all the good people leave.
I don't think YouTube was profitable before acquisition. Now it's profitable and a great product.
So I'm not saying 100% of acquisitions are shit storms, but so often when you see these old stalwarts buy new, innovative startups, everyone is scared their products will go to shit. Just look at the giant collective sigh of release when the Figma deal fell through.