> They're too stubborn to allow you to select an option for right angled corners again.
"right angled corners again"
I have a feeling you aren't and haven't been a Mac user for a long time. When was the last time Macs had right angled corners!? 30+ years ago?
I think it was in the Steve Jobs biography (or maybe I read it somewhere else), that Jobs made them do rounded corners on the windows back on the first Macintosh after noticing the rounded corners on a table they had. The engineers complained about how much extra memory that would take on such a limited system, but they figured it out.
Literally never. System 1 has corners that are superficially pointy looking, but if you look close they have a sort of smoothing instead of being a hard right angle. On a screen with 340 lines of resolution.
I've used Macs since 1988.