Has wearing non medical grade masks killed people?

On twitter someone posted a reply to me saying, if non medical grade masks do very little, what is the harm in wearing them, even if it is to make others feel safe?

This has been an argument I have had presented to e many times.

You may think, what harm does it do?

I will suggest that these non medical grade masks have resulted in the deaths of people.

If people believe these masks are 100% safe (and I do fine a lot of people do believe that) then may wear these around those who are venerable, such as those over 80 with health problems, and may pass the covid onto them.

So if staff in such as a care home are not wearing medical grade (N95), and they pass the virus on to the elderly in the home, it could result in deaths.

I have had many pro mask wearers who believe these non medical grade masks are of use, tell me that they have had covid. This suggests that it does not stop you getting covid, even when you wear these non medical grade masks, so proving my point.

I also question if someone has had covid, as one wonders how many were tested, and how any simply believe they had covid, when it could be the common cold or normal flu.