> The PATH (and other environment-vars) in Linux are shell-specific.
PATH works the same way in Bash, sh, zsh etc. etc. Various shells do offer some additional ways to manipulate environment variables, but you can rely on things like export.
If you meant "specific to a shell process", then yes:
> You regularly read instructions (I saw this in Go's official instructions yesterday) indicating to use the EXPORT command. This only works until you reboot
See https://stackoverflow.com/questions/1158091 . The export command is essential. But of course settings that persist between sessions, between reboots etc. will be stored in a file. How else could it work? The point is that you aren't forced to use a GUI and you can examine the file as plain text and comprehend it.
> you have to hand-edit a sudo-protected file (bashrc, .profile etc), and there's a learning curve to it.
It's only root-owned (what I guess you mean by "sudo-protected") if it's system-wide. Per-user settings only require that user's rights, exactly as one would expect. That's not different from having to be an admin user on Windows to change system environment variables. Most of these config files are actually auto-run scripts, and understanding the system is an important part of familiarizing yourself with Linux as a developer. Trust me, Bash is much more pleasant to program in than Windows Batch files.
> I don't remember the details, but I've screwed it up multiple times.
If you want a wrapper for the process, it's not hard to make one if you can't already find one. It's strange to me how many developers don't seem to have any interest in building or customizing their own toolchain.