Talking with is way better than talking at.
A common feature of bad conversations is when person1, call them Jesse, is obviously not listening to what person2, call them Celine, is saying and doesn't even attempt to engage. Sure, Jesse may be nodding his head and mhm-ing along, but he definitely isn't listening and even if he was, he wouldn't care; he's crafting the next few sentences that very well still could've been formed had Celine just stayed quiet the entire time.
This type of conversational selfishness creates a terrible environment: imagine if everyone was a Jesse, ignoring their counterparts and speaking at them instead of with them. There would never be any actual conversations, only one-way noise and impatence while waiting for the other person to finish. This phenomena is precisely why self-promotion should be quarantined and strictly moderated in large communities. It can quickly and easily get out of hand since one-off defections pay well in a place where traffic is at minimum due to quality standards and any post can quickly be seen by many. Self-promoters rarely care about bidirectional engagement, thus they shouldn't be given any at all.
The beauty in conversations is the engagement. The back and forth. The saying something and having it be heard—really heard, not just in the ears, but in the heart and mind, and in rare cases, soul. The pushback. The exposure to new ideas, regardless of their prettiness, ugliness, or intelligence. The discovery that another person out there agrees with you; or, in the case of many internet comments, vehemently disagrees and thinks you're an absolute idiot for even thinking, much less writing, about the idea. The chance to put an idea out into the arena and see what challengers come and what the result is. The rejection and escape of single-person echo chambers.
While these features apply to both analog and digital conversations, these norms aren't enforced on the digital side because there's less awkwardness and more ease in violating them—being a conversational douchebag in person results in not having friends, whereas there aren't any hard consequences for not replying to an internet comment: forgetting to reply, being overwhelmed with the sheer number of comments, not having something interesting or productive to respond with are all arguably valid reasons to shirk responding. And I'll admit there's something nice about not being obligated to reply and just letting comments come in versus taking the time and effort to send a comment out. It's a lot of work to type out a thoughtful response! (This is one reason why I think using AI for writing in any interpersonal form is so frowned upon—it comes across as lazy and apathetic, as though you just want to check a to-do off a list and be done with it.)
Or at least to everyone who's engaging in good faith. Most people wouldn't ignore someone talking to them in person, so why do it on the internet? The person took time to comment, and while it may have just been for them to develop some thoughts or gain sweet karma, it almost certainly can't hurt to see what comes of responding. Become known as a prolific commenter; gain a friend; learn something; get downvoted to hell and be scared to ever comment again; change your mind; strengthen an idea. The possibilities are both endless and enticing.
Exceptions exist. Given the choice of contributing to the discourse and not engaging with others versus not contributing because engagement wouldn't happen for whatever reason, choose the former. Putting ideas and information out there is generally a good thing. Engagement can still happen elsewhere: commenters can talk amongst themselves, the piece can get reposted elsewhere, and so on. But zero engagement should not become the rule.
Enforcement is (or at least could be) straightforward: top-level post authors must maintain some ratio of responses written to responses received. "Great post!" and other vapid words don't count. The good responses can be determined by number of upvotes, an LLM that gets asked "is this a high-quality reply?" or something of the sort, or trusted moderators deeming it such.
In an ideal world, the free market of the internet would reign supreme and contributors should be trusted to keep the place nice because it's in their best interest. Simply setting a rule like "treat others' comments and posts like you want yours to be treated" gives the soft nudges of "you want people replying to your stuff, so reply to theirs" and "you want people putting effort into their comments, so put effort into yours". But market failures exist. People get busy and replies get missed.
So while a lot of things in society do come back to the Golden Rule, sometimes it needs a bit more enforcement.