It used to be really great, you just have an "ender chest" folder that shows up on all your computers with a public folder that shows up on their web server. They screwed up the public folder pretty badly and I left after that.
Now we have syncthing anyway which is better anyway for a number of reasons and most people know git which works better on mobile devices.
They certainly started off that way but modern static analysis can catch a lot. Plus these other languages (yes, including Rust) are all still at least partly implemented in C/C++ so you cant outright ban it.
You can get absolutely tiny chips (maybe 4x the area of the shadow of a ball-point pen ball) that can run Linux for ~$1. Computers in IoT cost nothing unless you need to do graphics or run electron/Ml.
If you don't feel like configuring hostapd and dnsmasq I'm pretty sure there's an nmcli one-liner that will have network manager run a WAP for you. I use 'hotspot' on my phone all the time.
Curated app stores are great at preventing malware because they prevent you from installing packages from anyone other than the official maintainer, including yourself.
I think a lot of content producers have solved the problem by creating presences on many platforms and asking for donations. Developers are in the position of being able to host their own content (although you lose push notifications if you tick apple off which is something this site probably would do.)
Avoiding “equations” when you want to understand theory is a mistake IMO in the same category as avoiding “code” when you want to understand software: it’s possible but it’s definitely the harder way to do it.
To be fair it’s a far worse problem on Windows (although I guess a lot of my Linux machines are running from ram now so maybe I wouldn’t notice if it weren’t.)