Safari does not support WebGL; can’t display some websites, including parts of Apple’s own website and iCloud.com

I have found lots of other reference to users having the same problem, and zero solutions.

Clearly Safari is supposed to support WebGL. However, the old preference toggle has been removed, so if the reason for this failure is that I previously chose to disable it (months, years ago?), there is no way to re-enable it.

Not only does this break perfectly respectable websites that use WebGL, it breaks parts of Apple’s own website and iCloud.com (for example: the Notes section cannot load without WebGL and throws up a dialog saying WebGL has been disabled and I should try another browser — so Apple’s own recommendation is that I switch to Chrome to use it’s own cloud services?).

It’s bewildering that this has clearly been broken for some time and clearly affects multiple users, but there is neither a fix nor an acknowledgement. If I could find a hack that needed me to dig into the system with Terminal I’d be happy to try it, but there’s simply no advice out there (or on here!) that offer a fix. None of the online Apple help support pages address it, and none of the replies on other threads in Apple Support seem to actually understand the problem, even though other users have explicitly spelt it out.

How can it be that Apple builds their own website and services in a way that their own browser doesn’t — but should — but totally does not — support?

Or do we all just have to give up and assume this will be fixed by Big Sur?