In the context of sharing data between people, people use checksums with the same meaning as cryptographic hashes, as anything else would break for nearly all use-cases.

Digital signatures are actually overkill. The same infrastructure one uses to discover the authorship of a paper can distribute file hashes without any loss of autentiction, and I don't think anybody needs the non-refutation feature they bring. Maybe there is a nice use case for a paper authorship database with a PKI, but to my view the idea goes against an open scientific community that I think is much more valuable. (But again, maybe there is a way to have both.)