The caniuse site itself doesn’t properly work on my modern updated iPhone. The modals won’t go away. If a modal appears and it’s hidden behind the footer, I can’t read the rest of it. Yet it seems to be a site widely used and referenced.

Along with the 90%+ prevalence of it working on browsers, isn’t the joke mostly moot? Besides Chinese browsers and old IE/Edge, support seems to be fine. I don’t know exactly what Microsoft is doing with Edge Chromium on Windows 7/8, but if that’s pushed through more, the support is essentially universal if you’re not targeting the two Chinese focused browsers.

This is a problem specific to your iPhone — perhaps an over-zealous content blocker? If you can figure out what's different from a clean install, report it at https://github.com/Fyrd/caniuse/issues.