There’s a decent amount of mister kit sites that sell a complete set up. As far as having to know Linux I’m not sure it’s any more than you would for transferring roms to a sd card. Another thing mister has going for it is you can buy these preassembled “kits” today. Every time I get my eyes set on an Analogue system they sell out immediately and go onto eBay for much higher prices. Misteraddons today I can buy a complete set up (with a sd card pre-flashed) for ~$550.
I would be 100% all about analogue if I could buy a system. That being said maybe it’s just because I am interested in NES/SNES so those are the higher demand systems. I have a Mister but actually play more on my modded NES.
Like you said different products for different folks but I don’t think the barrier to entry for mister is very high anymore.