Most of my care of compression was because I was using my Rasp pi 3 and SD cards were not cheap at the time..nor are they now at least a 1TB isn't and when I mean cheap I mean less then 30-40 of what ever currency you use...
Like progrets said, it really is better to use a cheap PC as they are way more capable. If the Rasp Pis stayed at 30-40 instead off 100 or more...then well the trade off for me was worth it. As you know though it did not stay that way and you cab pick up a used PC for a little more than a rasp pi4 now with a LOT more power and storage space.
I think the Pi zero 2 can do PSX (ps1) games just fine (and thus everything under it..aside from N64 and 3DO) I would think about getting two of them for the price of one pi 4...but you have to FIND one at that price..and well the pi4 can run dreamcast (some anyway and PSP..again some!) So again for just a few more of whatever currency you can get a "monster of a PC" compared to a rasp pi4 for dedicated emulation *shrugs*
...although there is that small noiseless form factor of the PI..and well maybe the price of a PI is worth having once it is set up (IF it ever is!) to sit behind the TV and be used so that it is easy to use so that others can use it..I can have my hard drive space back and keep people off my main machine..*shrugs* just comes down to what you want to use it for..which is why it was made in the first place....
Yet i sit back and remember the first single MEGABYTE file (compressed I might add!) and i used to think it was HUGE for my 150 Megabyte hard drive on it! and yet things have not changed all that much have they lol
