I guess my ultimate vision for something like MAME is closer to that tho.

Everything in MAME would be a basic 'template' that you could add to your 'collection' (a profile) and even have multiple copies of with different configurations etc.

an MS Pacman machine would be one thing

a Floppy disk would be another thing

you could even own multiple copies of the same base game cart and choose which one to insert (so that each maintains its own nvram status)

if we're going to have named virtual environments where you can add / remove machines at will and form links between them then such becomes neccessary.

of course, the basic operation could hide that in a lot of cases (eg 'mame pacman' on the commandline could automatically create an environment called pacman, add the machine known as 'pacman' from the machine templates, and basically act exactly as it does now unless you start actively adding / removing other machines from that named environment)

there is always going to be a difficult step between professional, serious software, which is the direction in which MAME is heading, and gimmicky toy software, which is the direction things like RA are trying to pull the scene. Some of the complexity can be hidden by default in some use cases, but it still needs to be there, not locked out as you get with RA.