You're missing what I'm saying on a couple points. If a significant number of Republicans were willing to back impeachment and removal from office was a real possibility, I say go ahead with it. Whether the underlying conduct was bad enough is a question of whether or not members of Congress should support impeachment. My issue is going forward with impeachment without that support. That's what does the damage.
If you don't have enough bipartisan support and removal isn't going to happen, censure would be appropriate. The same symbolic stance without weakening impeachment.
As for the early stage dementia thing, impeachment is not the correct tool there. The 25th Amendment is the tool for that. If that was invoked tomorrow, I'd be okay with it.