Answer
Should I comment on other people's posts?
Quick answer
Yes, when you have something to add. A specific comment puts your name in front of people already discussing your subject.
What it's not
It is not a volume game. Generic praise ("Great post!") or pasted comments tell readers nothing about you and read as automated.
Commenting is the part of building a presence that most people skip, and it is the one where you meet readers on their ground. A post of yours waits for people to come to it. A comment goes where a conversation about your subject is already happening, under a post whose readers have just shown they care about it.
What makes a comment worth writing
A good comment only makes sense under that particular post. It asks the question the author left open, adds an example from your own work, points out the case where the argument does not hold, or supports the post with something concrete rather than a compliment. Four styles cover most useful comments: insightful (adding a fact or an angle), a question, supportive (with a reason), and contrarian (a reasoned disagreement). Loudquill’s Engage feed suggests comments in these styles, and you edit them before posting.
What does not work is the comment that could go under any post: “Great insights!”, “So true”, a paragraph restating the post. Readers skim past them, and authors notice who writes them.
The honest counter-argument
Commenting takes time that could go into your own posts, and a comment does not stay on your profile the way a post does. For a founder with very little time, that is a fair reason to prioritise. The answer is that the two are not in competition: a few specific comments a week on posts from people in your market often lead to more real conversations than an extra post of your own, and they cost less to write.
Choosing whose posts
Comment where your intended audience is reading: the people you would like as customers, peers or hires, and the voices they follow. A comment on a post from a large account in an unrelated field is seen by many and read by few who matter to you.
Related questions
How long should a comment be?
Long enough to say one specific thing: a question, an example from your own work, a respectful disagreement. Often two or three sentences.
Is it fine to disagree in a comment?
Yes, if you disagree with the argument rather than the person and explain why. A reasoned contrarian comment is often the most useful one under a post.
Should I use AI to write my comments?
If you do, edit before posting. A suggestion is a starting point; the comment goes out under your name and should say something you actually think.