Well my argument is the exact opposite – if I know Docker why would I spend countless hours individually mucking about with maven and jvm and whatever dozens of custom components the service uses that I might not even know of? And repeat that for every other stack.

If I need to test my code locally against a service some other team develops, the only exchange needs to be "here's a docker compose file you can run with one command", not a wiki with shell scripts and other dozens of instructions which were likely outdated 3 years ago.