For instance, Alyssa mentions in this post that most emulated games will need at least 16 Gigs of RAM at minimum.
In addition, native ARM games on MacOS don't have the additional overhead of emulating a different CPU architecture and Graphics API.
However, that doesn't take away from this emulated support being an amazing achievement.
And the minimum is pretty minimum. A 16 Gb arm mac will go into yellow memory pressure while running emulated games, I've noticed.