If you're saying everyone should agree on the same IDE and personal development toolset, I disagree, sort of.
The GP was suggesting the effort to add CI, linters, fuzzing, auto-formatting, etc was too hard.
If that can be abandoned entirely, perhaps the legacy codebase isn't providing enough value,
and the effort to maintain it would be better spent replacing it.
But the implication is that the value outweighs the costs.
Put all the linters, fuzzing, and format checking in an automated build toolchain.
Allow individuals to work how they want, except they can't break the build.
Usually this will reign in the edge cases using inadequate tools.
The "built on my machine, with my IDE, the way I like it and it works" is no longer the arbiter of correct,
but neither does the organization have to deal with the endless yak shaving over brace style and tool choice.