Android

The charitable version is that when PCs (I'll include the Macintosh in that category) were the dominant way people used computers, the average person struggled to use them effectively, often misconfiguring them or installing malware. I had hoped the fact that pretty much everyone born after the mid 1980s grew up with computers would help, but it didn't.

Mobile OS makers wanted to create systems that were harder to break so people wouldn't have be stuck with devices they couldn't use or expose their data to criminals. They did so in part by limiting the feature set. Vanilla Android won't connect to ad-hoc wifi networks despite huge user demand on their bug tracker. Google locked the issue without explanation.

I'll admit I haven't really thought about installing Fonts on Android despite my eagerness to customize it in other ways (I have root on all my devices). None of the things I do with an Android device require it, and heavily customizing the look and feel of the OS doesn't interest me.

This won't be popular, but any time I see an android screenshot with a custom font it looks offensively bad to me. I still think it's important for accessibility reasons though, as certain fonts can be a big help for people with dyslexia.

Fonts are a lot more complicated than they appear. Font formats like TTF are binary executable. Basically that means a malicious font file installed can run commands on your system just by displaying what looks like the letter m. Fonts are also processed through an interpreter engine that renders their physical display on screen. Interpreters are nortoriousy a vector of attack because of their low level system access

Check out FontForge if you're interested in more

Monolithic OS. Plus being Immutable.

Immutable makes sense for a mobile device where you need a guaranteed way to ensure it functions as designed.

The rest is because phone manufacturers and Google (and Microsoft, et al) forsee a future where you don't control your OS, so they then control everything.

You need to be rooted but this should do the trick using Magisk.

If you want to add all the Windows fonts, if you are on Arch just use this PKGBUILD and build it inside an Arch distrobox if you are on anything else. Just extract the fonts from the generated tar.zst file.

EDIT: Forgot to add the link (oops)

My bet is "because historic reasons".

I remember my Nokia 3220, which was the paradigm of phone personalization at its heyday. You could personalize almost everything of it - from its back cover to getting another chassis and/or keyboard with different colors, to its wallpaper, how things showed up in the "home" screen (wether if a list or a grid) to the ringtones and the light patterns they showed when the phone rang. You could even personalize said light patterns doing some dark magick with MIDI (I did one with the opening riff of Metallica's "Hit the lights" back in the day). Frankly that phone was the tits and imho everything regarding fun but useful phones has gone downhill from there.

But about the font? No, you could not set a different one. There was no other different font, and am pretty sure it was the exact same typeface as the one in the 1100. It was hardcoded.

Same story with a Motorola Rokr Z6 I had the chance to have - you could personalize almost everything from it (it ran Linux under the hood!) except its font.

I'd say Android dragged those concepts from those old phones, and it was just like a couple years ago or so they went "oh! shit! oh! shit!" and remembered about the fonts - all we had meanwhile was the Roboto font in Android 5, which imho was a huge downgrade from the ol' good Droid Sans family - so now they did some cheap ass effort to try to catch up. And meanwhile typeface formats have evolved a lot - not just bitmap fonts, not even just TrueType fonts, but OpenType fonts (I recall reading somewhere they're Turing complete?) and now variable fonts. Supporting all of that stuff doesn't seem easy, and it's not like AOSP or Google like to put effort in stuff people actually care - they'd spend some time or it or they can choose a subset of all of that to make their lifes easier. If they want to, that is.

And not that in iOS things are better, though - I recall having to do some weird shit with mobile iTunes or something to set my mum's favorite ringtone because it won't allow custom ones that easily as we can in Android.

I think the main reason is Google wants to provide a predictable environment for the developers where not too many things can be changed so it doesn't visually break apps. Because for big corps really, really want their branding to be perfect, can't be caught with a screenshot of their app in Comic Sans.

You used to be able to install some pretty sick theme packs but over time everyone started shipping apps with its own hardcoded themes and theme libraries such that it looks identical between devices, so now we're stuck with whatever Google says is how it should look.

Back when I was a developer I had to turn off my theme for every demo because the clients would keep focusing on that and not their fucking app, and keep complaining it clashed so hard with their brand colors. Which I'm sure is part of why the stock theme now is so flat and neutral vs the Holo/Honeycomb days.

Installing custom fonts has never really been a popular thing on any platform except in niche cases. Perhaps the best known use case is for print design and publishing where designers expect to be able to use any font they want in a magazine layout and have the printers able to put it on the page.

Samsung has plenty of fonts and you can use zfont for custom fonts as well. Not sure if other Android phones have the option tho