Open to the possibility that I’m just cynical but my faith is very low that these comment processes are anything more than a regulatory requirement for the illusion of due diligence which legitimizes the actual corporate lobbying and security state actually making the policy.

You’re wrong. Even if the regulator ignores them, they allow third parties to bring a suit under the APA.

It lets politicians see how unpopular something is and how many votes they will lose.

They require your name and address, so they will have a nice database of anyone who dares voice an objection.

I'm nearly certain commenting, at least from my monitoring of commenting on ATF rulemaking, achieves the opposite of what the commenters hope.

While there is ~zero chance that commenting can help you, it absolutely is used against you as their lawyers sharpen their claws by crowdsourcing possible sources of challenge and use your comments to predict them and determine how to undermine such positions.