Agree. But a lot of this is tooling though, whether its adequate and whether its ubiquitously available. e.g. you can diff two directories in Linux, which is super useful, but directories are not text files. The issue is, can the differences be reasonably represented in text formatted output.

I'll take a good format and a diff filter thank you very much.

It's easy to write a diff filter for e.g. xlsx, it's not possible to make CSV any good.