I wouldn't know, I don't look at my spam folder.

Gmail spam filtering is poor enough that a lot of obvious spam reaches the inbox as well. The quality of the spam filter alone is a good enough reason to move off gmail.

I just mark as spam and move on. Maybe my email isn't on as many spam lists.

If you only get 2-3 you are lucky :)

I have almost zero spam (that isn't filtered properly). Once in a while I catch a false positive in the spam folder but that's about it.

Maybe 10 annually.