The closing conclusion of the article is amazing. Lopp did again a great work with this study.

"Bitcoin is an antifragile network. That which does not kill it makes it stronger!

We have seen a variety of attempts to flood the network over the years and the worst they have been able to accomplish is to create temporary inconvenience and annoyance for other users of the network. It should be clear by now that transaction spammers are simply burning their money."