MacOS does seem to “use all the ram” but never falls over itself.
I think the kernel is likely genuinely better in low memory conditions (its hard to be worse than Linux here to be honest) - and thats combined with being aggressive about using as much of the ram as there is available opportunistically. (not fully unloading applications when closing them for example).
“WindowServer” uses 2-3G of ram, and electron apps use lots too; but truthfully my macbook is able to sustain significantly more open programs than my linux laptop, despite my linux laptop actually having more memory. (32G vs 24G for the Mac).
I cant explain it and I am genuinely curious how this is the case, but at least anecdotally, parent is more correct than not.
It won't help the RAM situation, but storage at least is upgradable like that.
I'm leaning towards an upgrade next year to the 9950x3d if reviews pan out. Sure, it's going to be a bigger machine with louder components, but the upgrade will likely be half the cost of anything close from Apple since I can take my existing GPU, PSU and storage at the very least along with me.
And "upgrade costs" is highly misleading for most of the components. You are buying a different machine config that you can't change, up or down, later on. I get that most people don't want to bother opening up a PC to swap out components, but the easier they made it, the more people will do it, and Apple is running the other way.