It’s hard to say. Such spikes were discussed some time back:
Scroll down to the 2nd last screenshot posted here: Debian Xfce vs Gnome
Some further discussion from this post onwards: Xfce vs Gnome DE - #12 by carmar
Given that Gnome generally does use more resources, makes it at least a contributor to resource hogging. Thus, an accomplice if not the perpetrator.
I felt that some games ran better on Gnome. But did I take several measurements and compare them to Xfce? Nope. So that doesn’t leave me anywhere other than relying on others’ data.