It really comes down to the fact that it's better to be functional, forms don't need to /look/ good they need to work well. For aesthetic things we can still use the pretty fonts.
A couple of years ago I went into archives of Dutch newspapers to learn whether and how the famine of hunger in Ukraine (known as Holodomor) was reported back in 1930's. Fuck me, it was hard to read those excerpts. But it is what it is. OCR could've converted the font. The problem is, is the OCR accurate? Like, is my search with keywords having a good SnR, or am I missing out on evidence?
Personally, Times New Roman was likely the reason I did not like Mozilla Thunderbird. I have to look into that.
The thing about usability is that it's both objective and subjective, and one can argue that aesthetics is part of usability. For example, I find writing code much more pleasant with Comic Code font, and I can imagine that there are other people that would hate it.
Ever tried changing the font of a printed document? Or a PDF?
PDF -> Nope.
.doc(x) -> Sure.
Website, OS, apps (including terminal) -> Sure.
Now regarding PDF I might've tried a long time ago when reading some old document (like CIA about MKULTRA). I don't remember if I succeeded. But there are PDF editors out there. I do think it likely screws layout (esp. larger documents), but that can be true for .doc(x) as well.
And I can certainly confirm that changing the font of PDF will almost always result in a unreadable mess. Something about how a PDF doesn't have text "blocks" and instead fixes each character making text reflow almost impossible.
The Dutch dev of Calibri commented on the history [1].
He makes a couple of good points, nuances. The main one I liked is related to your premise: it was that the Times New Roman font was optimized for printing newspapers whereas his successor was meant for computer screens.
Ultimately, IMO this is just bullying people with bad eyesight and dyslexia (and said bullying I can only regard as hatred towards minorities which reminds me of a different era). My father had MS and due to that bad eyesight. He had special glasses with a special lens to read. Of course any font change has a learning curve, but to me this just hits home as I've seen him struggle to read.
Bifocals, I'm guessing.
A friend of my parents also made a custom card deck, with huge symbols and letters. That way, we could work around his disability. We always had to work around his disability, and it regressed but slow variant and he was also too old to get the medicine which effectively stopped the MS from getting worse. However, it meant other people who had the quick version or were younger got more QoL.
I don't think he ever used Calibri. I mean, at that time, he wasn't into computers anymore. He had all kind of health isssues due to MS. It pains me to think people like him now have more difficulty to read letters because of BS decisions like these just cause NIH or whatever the silly reason must be. But there's also good news: if it is digital, they can override the font and such.
The technical aspects you mention are important. I have diplopia, and also close one eye. It gets worse in the evenings. I love paper books and own many, but all my reading now is on a Kindle, with a huge font. It makes it so much easier.
* condensed glyph widths, for ease of setting in narrow columns
* high x-heights and short ascenders and descenders, so lines can be set tighter and more text thus fitted on the page
* robust forms and serifs to allow for the tendency of newsprint to absorb and spread ink
These features don't necessarily translate to improved readability in other contexts.
There's an irony: the _Times_ (of London) commissioned it in 1932 to improve the readability of its newspaper, which previously used a Didone/Modern style typeface.
I like Times New Roman and I find Calibri, a rounded-corner sans serif, to be an absolute abomination of milquetoast typography.