Just a few years ago, you would never see such a disparity in votes vs comments. But these days, this is pretty much the norm. I've seen posts with 10K+ upvotes and no more than 80 comments.
I'd say in about 2 years, the entire place is going to be bots with AI generated content that try to mimic "real users" using their new Dynamic Product Ads tool. Not sure how that's legal as I thought ads needed to be marked or differentiated from regular content, but here we are.
The future looks bleak and AI even bleaker. Because it's going to be used against us to make the rich richer and not to make our lives better.
In addition to factors already mentioned by other users, I believe that there are also social/cultural reasons for that lack of engagement.
Commenting in Reddit is like stepping on a mine field - no matter how innocuous your comments are, you're bound to have users there assuming words into your mouth to screech at you. Plus all the "ackshyually", one-upping, "wah TL;DR!" (i.e. "I'm entitled to an abridged version of what you said, even if you likely spent far more time writing your comment than I would reading it").
Eventually you say "why bother commenting? Just to get a headache?" and stop commenting altogether.
Does it sometimes seem like commenting in high traffic online spaces feels this way too, not just Reddit?
Kind of. In most high traffic spaces it feels simply pointless; as in, nobody will read it.
In Reddit (and Twitter) however it feels like people will read it, misread it, and punish you for what you didn't say.
Before I quit Reddit (when Bacon Reader died) I had already curtailed my commenting because of this. It seemed that any time I tried to make a thoughtful comment on a even slightly contentions subject I ended up in a pointless argument with someone who had poor reading comprehension. It was disheartening to realize that while I was agonizing over every word I put into my comment in an attempt to clearly explain my thought, the same courtesy would not be extended by the people mis-reading it. I started to think people were just scanning comments for keywords to get angry about then telling me that I was ignorant of a subject I knew a great deal about or a reactionary child when I am 50 IRL. Commenting became a burden and it lead to a decline in the quality of conversation as more and more thoughtful commenters found that burden too great.
The same thing happens on Lemmy, unfortunately. A lot of people just want to be keyboard warriors.
It's actually the mods that did it for me. If you don't have this really weird super specific but vague world view, and you can't follow 143 different rules (some not specified), then they start censoring you and temp banning your comments and contributions. The mods on my community sub actually permabanned me when I questioned them on it, instead of discussing it. After that I was like this is infuriating, and I don't really want to participate here. Problem is, they mod anything related to said topic, like city, province, country, most political parties, quite a few special interest topics, etc. Its super weird behaviour.