Linux mint will install and run from a usb drive as long as you unmount it upon loading its live version. Then it will allow to install on it during the installation procedure. I have an old Mac Mini and an old Macbook Air running Mint 22 that way.
If the PC you're building has the latest and greatest hardware in it, you might find that Linux might not support that stuff yet. You might get lucky, but you might not either. It usually takes a little while to get new hardware supported. So it might be a better idea to install Linux on your older computer, then there's no reason to buy a new PC anyway. Linux uses about half the RAM that Windows uses, for example, so it's like you did an upgrade anyway. As long as you have over 4 GB of RAM, you're fine for desktop usage. Windows requires 8 to run as well that Linux does at 4. You'd only need to upgrade if you're after extreme gaming support.
Depending which version of the MacPro you have exactly, that machine from 2010 is around the speed, or slightly faster, than a Raspberry Pi 5 with 8 GBs of RAM these days. The problem is the energy consumption, not really a green machine to run.
Naaah... you know enough by now. Just try to replace Windows from your friends' PCs with Linux. And tell them to do the same soon too.
In that case, if it's just CLI, you don't need a new computer. Use your phone or tablet to ssh inside your main Linux computer.
Raspberry Pis are also ARM-based, and you can use them as desktops. Only problems are that they aren't very powerful for media usage (e.g. video editing, 4k video decoding on youtube, blender etc). If you're not into such high performance media production, then sure, they're fine for everyday usage.
You can always provide them with enough standardized APIs that don't break, to make them useful. The situation that's right now is unacceptable.
That's more acceptable than to have them break every 6 months.
No, there is a third option: you freeze the API for the extensions. That way, nothing breaks. And if an app uses private APIs (or public APIs that are not meant for extensions' use), then and only then you treat it as unsupported.
And yes, the constant breaking is a big, big problem. I use 6 extensions to make the desktop the way I want it to. In every release, I get at least 4 of them breaking for several weeks each time. The last time, the dock extension I used broke with the new Gnome version, but when it got disabled, the "favorite" icons on its dock did not reflect on the Gnome's default dockbar. All that stuff, are unacceptable for a proper usage in 2024, especially for people coming from Windows that expect stability (no matter what people say, Windows IS stable). I use Linux since 1999, but it's that kind of stuff that i can't stand. I want stability. The days when I was hacking on Gentoo in 2003, are long gone. I'm now in my 50s and i don't have time for that shit.
So, yeah, the third option.
I use Gnome, and I'm not a hater, but if you're expecting some harsh criticism for it, here it is: Extensions breaking so easily should not happen. It's an extreme pain in the butt every 6 months. They should establish an allowed API that's frozen, while extensions that use private api calls, don't get posted on the gnome website/extensions app, so they're harder to find. Simple.
The ads have become too long. Some of them are 40 seconds long, for a 3 minute video. That's unacceptable. I have thought about it, and I think the best would have been a single 8 second ad, unskippable. But never more than that. That, I could take. But multiple ads (even if they're just 5 secs each but you have to be vigilant to press "skip"), or long ads, or interrupting ads, are just too much to accept.
With 32MB of RAM you can't go far. The Linux kernel barely runs on it, and that's just the kernel. NetBSD also has a minimum requirement of 32GB of RAM. One other thing you can do is try to run BeOS (not Haiku, but BeOS). It could run on 32MB of RAM (it still preferred 64 MB, but it could run on 32 too).