Looks like the winners in the USA sports market are the big corporate affiliates and high-traffic portals, as if they didn't get enough traffic already.
Covers, VegasInsider ActionNetwork, TheLines, Gambling Dot com, etc. all gaining.
Hypothesis: Small sites with insufficient inbound authority links are subjected to extra scrutiny. Ones that don't pass muster are being treated more like affiliate sites and less like authority sites. In some cases, they might be treated like content farms.
The reality is that there are only so many ways to write about betting on the Premier League. The difference between a Mom & Pop affiliate and a corporate affiliate is often just authority links. Granted, some smaller affiliates do a much better job on their content!
This sucks because the aforementioned mega-affiliates have exclusive "paid" partnerships with major media to supply them with inbounds and advertorial/parasite placements. Google's algorithm/intel isn't sophisticated enough to detect this yet.