Of course it is. This doesn’t mean the filters aren’t working. “Filters working” means that filters raise the cost of getting abusive transactions confirmed. The notion that filters don’t work because a transaction that pays 10x the normal rate occasionally slips through is a silly strawman. Spam filters have never been perfect; your email provider most likely filters spam, and I guarantee you are happy with keeping the filter even though an occasional spam email ends up in your inbox.