I have always had a habit of upvoting comments under my posts and also answering every one of these. If a comment has some effort in it I will give it a 60-70% upvote. My hive power is not that high, 6.7k currently.
But I have seen a couple of people who very often comment under my posts, that nice shots or clearly have not read what I wrote, and give generic comments of some kind.
Now I still give an upvote to these, but usually 0.01 worth only, and often don't reply to those because I don't have anything to say besides thanks.
I myself don't comment too often on other posts. Only when I actually have something to say, like here for example 😅
You're kinder than I am, voting up a comment when you know they've not read the post. I often leave a reply like, "it's clear you have not read my post and I'd appreciate it if you would either read my post prior to commenting or just don't comment at all."
Sometik snil also ask a question back to them about my post and in those cases...usually get no response back. Says it all really.
As for your last...not commenting often. I look for accounts that comment on others (I mean newer accounts) and with some personality and effort and then try to support them. Of course, if they post in languages that are not English I never read them, I don't use translators, so those people miss out.