I agree that they can add up to a lot of noise but at the same time their spirit is nice enough that it feels churlish to try to negate them. In cases like this we usually go by what pg wrote 15 years ago:
Empty comments can be ok if they're positive. There's nothing wrong with submitting a comment saying just "Thanks." What we especially discourage are comments that are empty and negative—comments that are mere name-calling.
https://news.ycombinator.com/newswelcome.html