New cameras produce raw files that are not backwards compatible with older raw file formats. These raw files are key to the highest quality and flexibility in editing.
Problem is that the latest macs are just so fast that it makes it hard to switch back.
And professional photographers tend to be largely nontechnical people who aren't keen on tinkering with some conversion workflow, possibly including ImageMagick or other Linux-native tools of questionable compatibility with the file formats (and again, on decade-old macOS) going just so they can do their work.