> doing the "draw at 2x scale and then scale down" dance that was popularized by OSX and copied by Linux
Linux does not do that.
> It's strange that Wayland didn't do it this way from the start
It did (initially for integer scale factors, later also for fractional ones, though some Wayland-based environments did it earlier downstream).
> Linux does not do that.
It did (or at least Wayland compositors did).
> It did
It didn't.
I complained about this a few years ago on HN [0], and produced some screenshots [1] demonstrating the scaling artifacts resulting from fractional scaling (1.25).
This was before fractional scaling existed in the Wayland protocol, so I assume that if I try it again today with updated software I won't observe the issue (though I haven't tried yet).
In some of my posts from [0] I explain why it might not matter that much to most people, but essentially, modern font rendering already blurs text [2], so further blurring isn't that noticable.
[0] https://news.ycombinator.com/item?id=32021261
[1] https://news.ycombinator.com/item?id=32024677
[2] https://news.ycombinator.com/item?id=43418227