Objectively speaking, its extremely hard to miss your healing as a support outside of ana. So if you have low healing that either means you’re playing ana and having a low accuracy (which is fine), playing a character with low healing potential (which is fine given other utility you bring), or playing a support character while using bad positioning or ignoring the healing aspect of your kit.
With dps, its fine to ask if the person is alright/ point out the score if its so low, but its a lot more nuanced than point and click outside of the top hitscan characters.