about:protections is a good feature to have, so that we know what Firefox protected us of. However the informations currently shown are extremely basic, while so much more could be offered!
I think the most important element missing is a list of websites in which Firefox took action. For example, when we select "Fingerprinters", we should see which website was found to contain these things, and how many were present during the week of browsing data stored in about:protections. This could be useful, as it could encourage us to look for another website or service, where possible, that would be more privacy-conscious.
Another feature could be to show us where does the blocked element come from, specifically the domain to which it "reports". While this information can already be found in the protection "shield" icon in the adress bar, it is specific to the current website, but if implemented alongside the previous suggestion, it could show, for each element blocked, next to the site on which it was found, who would have access to the information collected by the tracker.
Being able to see where trackers, fingerprinters, cryptominers and cross-site tracking cookies were found, as well as where they "report", would give about:protections a greater (and true) usefulness, something which it currently lacks.
On a side note: why not also offer about:protections in the mobile and Focus versions of Firefox?