Most (successful) paths lead to balkanization. Just one acquisition can do it, much less 2 or N more. And the pace of these changes can outpace your ability to respond to it, which makes fighting it a losing battle.
Yes, it is inevitable at some level, but supporting 2 different stacks (result from acquisition) is better than 20 (result from "pick the best tool for the job" culture).
That's a "nice to have" problem down the line. What I've seen is the insanity of microservices being adopted by one-pizza-team startups.
Been there, except I was the pizza being eaten by 5 microservices.