I think better tooling for deployments allows small changes. Not the other way around.

That's sort of what I mean by small changes being a forcing function. The tooling we have available rarely makes this level of small changes untenable, it's just clunky. When you send 1k PRs a day though you'll notice things that are too clunky and fix them, and then that makes it easier to get to and maintain that level of productivity.