If memory is released as soon as possible instead of waiting for the next GC cycle, does not it make it more efficient?

Yes!

Hopefully I can clear up the discussion a little:

Q: Does reference counting 'use' less RAM than GC?

A: Yes (caveats etc. go here, but your question is a good explanation)

Q: Does the M1 in and of itself require less RAM than x86 processors?

A: No

Q: So why are people talking about the M1 and its RAM usage as if it's better than with x86?

A: It's really just around the faster reference counting. MacOS was already pretty efficient with RAM.

I'd like to propose tokamak-teapot's formula for hardware purchase:

Minimum RAM believed to be required = actual amount of RAM required * 2

N.B. I am aware that a sum that's greater than 16GB doesn't magically become less than 16GB, but it is somewhat surprising how well MacOS performs when it feels like RAM should be tight, so I'd suggest borrowing a Mac or making a Hackintosh to experience this if you're anxious about hitting the ceiling.

There is no “next GC cycle”, objc and swift use ref counting on every platform (there was an abortive GC attempt on desktops a few years back but it never saw wide use and has been deprecated since mountain lion).

these are not gc apps, they are reference counted.