Genocide vs. harsh words are also similar in kind and differ “only” in degree… but that still makes them pretty different overall! Similarly, over-eating to become a little overweight, vs. being massively obese like 500+ lbs (226.8kg), is again a difference in degree though not in kind (perhaps? or arguably is there a threshold where…?). Another comparison could be Lemmy/Mbin(/Sublinks/Piefed/etc.) vs. Reddit: different in degree… but both are social networks so should we say not entirely in kind?
The average behavior of people experiencing hexbear from the outside - i.e. who did not choose it intentionally - is objectively much worse, compared to an instance such as lemm.ee. Again, in degree, even if not in kind. (you can literally measure the effect quantitatively, e.g. by counting the number of complaints lodged against it, such as this post; it may not be as hard a science as physics, but then again, other than physics, what is?)