IMHO fundamentally the MR/PR author is the one requesting reviews (be it mandatory to merge or not), and they are the ones to decide if the comments are valid/require actions or not.
If the reviewer didn't accept your PR you already know they're expecting something more, and what it is will be in the comments.
I don't know if GitHub comments can be individually marked as optional or not, but even then the reviewer might not know the actual impact of what they're pointing at.
For instance if you're deleting a bit of feature that has been already disabled at the step before, a reviewer pointing it out as blocking might as well be lacking context. I find it more natural for a comment to be mostly factual and let you check if it needs a fix or not.
It's more work on your part, but it's also your PR (all of that within reason, and not being jerks)
If the reviewer didn't accept your PR you already know they're expecting something more, and what it is will be in the comments.
I don't know if GitHub comments can be individually marked as optional or not, but even then the reviewer might not know the actual impact of what they're pointing at.
For instance if you're deleting a bit of feature that has been already disabled at the step before, a reviewer pointing it out as blocking might as well be lacking context. I find it more natural for a comment to be mostly factual and let you check if it needs a fix or not.
It's more work on your part, but it's also your PR (all of that within reason, and not being jerks)