I've been using my M1 base spec Mac mini and it took 25+ apps to make the memory chug; Kerbal Space Program (Steam), Xcode compiling, Adobe XD, Safari (twitch), Safari (Crunchyroll), AppleTV+, Pathfinder Adventures (iPadOS), Pages, Keynote, Numbers, Notes, Messages...and a bunch of other apps open simultaneously.
I haven't heard the fan at all, it's 100% silent and the fan hasn't kicked in.
this...thing....is....ridiculous, I really doubt many people will need 16GB of memory
don't get me wrong: it definitely uses some OS tricks such as swap memory, etc. etc. but none of that matters, it only matters when the system is no longer fluidly usable tbh