I think it would be more impactful if you contribute to Linux Mint and Elementary. The former reminds me of Windows 7 and the latter is a MacOS lookalike.
Elementary is a non-starter because even if it resembles macOS aesthetically, it’s more like GNOME or iPadOS in how it eschews a proper menubar in favor of hamburger menus or removing functions that don’t fit in the toolbar altogether. It’s also missing number of other power user oriented features like a GUI for modifier key and per-app key shortcut remapping.
Mint/Cinnamon are nice but I think its ties to GTK+ and various GNOME components are a liability.
Not if those "improvements" go against the desired grain by gnome/etc maintainers.
If I'm not misremembering, the gnome team is especially notorious for being closed to changes that go against their desired design goals.
Trying to get changes upstream like what the parent was suggesting would be somewhere between arduous and impossible, let alone being a pain to implement.
Mint/Cinnamon are nice but I think its ties to GTK+ and various GNOME components are a liability.