When I was first switching to Linux, I installed Arch on a USB3 stick and ran from there for a month or two. It worked pretty well, however I did seem to have issues with I/O contention. During some read and write operations and multi-tasking, the whole OS would just hang up until the operations were done. Since moving that installation to an SSD, that issue is gone. So, it does work, it’s a pretty good way to “try before you buy”", but do keep in mind that performance will suffer.

At the same time, I’d definitely recommend working through the pain of getting it setup right. When you have a problem (and they will crop up), it gives you a better understanding to work from for troubleshooting. You may also want to try our different distros. I used Arch, because I hate myself. But, that may not be the right choice for someone else. Something like PopOS could be a good choice for something that is aimed more at gaming, but is supposed to “just work”. Ubuntu is a good choice for a more “mainstream” look and feel. There is no good reason to do things the hard way, unless you really, really want to. The goal is to have a functional system, don’t tie yourself in knots getting there.