@hugh Just from the perspective of a web developer, Safari has a long history of stalling the progress of the web.
If you allow me a tin foil hat moment here, it's pretty clear they'd prefer native applications to remain the priority.
I agree, it's a shame they don't at least have Firefox on this list. In past jobs we've not often had the time to support safari's quirks.
More on the Safari point here https://infrequently.org/2021/04/progress-delayed/