For aesthetic or other preferences you change the default font to whatever you please. The default font shouldn't be about aesthetics, it should be first and foremost about usability. Especially on printed media since there it cannot be changed in a whim.
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.
Off topic but did you find anything interesting? I spent a few days researching Holodomor and was surprised how poorly understood it still is even today, and badly reported at the time. Good propaganda case study. There’s a dramatic film about the reporting too, Mr. Jones (2019).
> For aesthetic or other preferences you change the default font to whatever you please.
Ever tried changing the font of a printed document? Or a PDF?
> The default font shouldn't be about aesthetics, it should be first and foremost about usability.
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.