Therefore the comparison is invalid.
By the same token, you could still reject to question because the verb to quest exists.
"Quest" and "question" are also not a valid comparison, because the two forms aren't even clearly the same word. For example, if someone goes on a quest through the jungle, you don't say "his question through the jungle was interrupted by a phone call from home." Or, "he questioned from one end of the jungle to the other."
And quest/question are not parallel to transit/transition. If you think otherwise, please provide an example.
And I didn’t claim that quest and question had a similar relation as transit and transition in meaning, only that in both cases, the two words have the same etymological root. I mentioned this in reference to your claim that my opinion was not supported by etymology. It doesn’t have to be, because etymology doesn’t dictate the current meaning of a word, it can just try to explain it.
Edit: We don’t have a straight verb but we do have fungible. So we could try to bring funge into the mix as the “proper” verb.
I do like "funge." Let's go for it! I'd be gruntled.
The verbs transit and transition mean different things. The former is the physical movement, the latter is a change of state.
In the process of evaporation, water transitions from liquid to gaseous state. It doesn't *transit from liquid to gas.