I've been thinking about ways to make Gnome lighter in the past - would it be possible for Zorin OS to implement a lightweight DE like Gnome in a way that doesn't compromise the user experience as much as possible?
I think that Zorin Lite now uses a completely different DE than Core is confusing users, and this would solve the problem.
I don't think a whole new DE is needed now. Disabling some features of Zorin Core will give practical performance on a 10 year old laptop. For example, Snap and Flatpak would be high on the list of dismissals.