I blame both, but I think the audience/reach factor is more ubiquitous. Specifically, I think the problem is an inability for most people to properly filter in sufficiently large rooms, not the audience/reach factor in and of itself.

This commenter is talking about whatsapp behavior in Brazil and gives an example of a seemingly similar situation where there doesn't seem to be as much engagement focused algorithmic influence at play https://news.ycombinator.com/item?id=33459878