Ask HN: Why doesn't hn have a notification mechanism?

//Half rant, half ask hn...please forgive.

Why doesn't hn have a notification mechanism equivalent to reddit's orange-red?

When someone posts something sensible in response to one of my comments on (any) social platform then I'd like to know about it so that I can thank them/respond/decide to ignore.

hn does not do this - worse...recently responding to old comments was disabled.

Now I appreciate hn's minimalistic design and that they don't bug me with adverts and random ad notifications...but this just seems broken when viewed in terms of the forum's broader purpose of facilitating dialog...