I dont see many people claiming toxicity doesn't exist, I do see a lot of people claiming other people are claiming it doesn't exist though.
I think most people with a double digit IQ are more than aware in any large community there will be unsavoury people.
When this subject comes up, for the 18th time on any given day on the forums I always think of this,
"If on your way to work you met a rude person, move on and forget about it, rude people exist. However, if by the time you get home you have done nothing but deal with rude people all day the chances are the rude person is you"
People will generally reflect your own attitude back at you. There are exceptions, but if its a common problem you have, use a mirror.