Why not? They’re the same core OS.

Because software needs to be aware of the memory lifecycle to avoid losing data when its process gets culled. iOS apps are explicitly built for that, but to my knowledge macOS apps aren't, they are allowed to assume they will run forever until the user closes them.

	▲	pram 7 hours ago \| parent \| next [-]
		They added iOS-esque stuff a long time ago in Lion/Mavericks like “App Nap” and “automatic termination” so it kinda has this, but it’s inconsistent.
	▲	dagmx 11 hours ago \| parent \| prev \| next [-]
		Isn’t this ignoring that inactive apps essentially get paged out of memory anyway? Also conversely what about iPadOS where you can multi task on just 8GB too. People have survived on 8GB Mac’s for a long time. I’m not sure things are as dire as you make them out to be.
	▲	qn9n 11 hours ago \| parent \| prev [-]
		They are both built upon Darwin, Apple's BSD-based kernel, they are essentially the same OS underneath with different top level API's and even those are getting more uniform with Swift and SwiftUI.