Plus, some of it is unavoidable if you don't have a single unified exchange. Where there's latency, there's inefficiencies, and where there's inefficiency, there's profit to be made. And competition among exchanges is healthy for the ecosystem, so I don't think we'd want to consolidate.
And lastly, HFT has consolidated so much that I don't think it's worth worrying about. Virtu literally switched sides and make most of their money on order execution. Industry-wide, HFT revenues are down like 80% over the last 5-8 years. Between wholesaling/PFOF taking non-toxic order flow off the lit exchanges, and banks finally wising up on not being pants-on-head about their order execution, it's literally just sharks in the pool now, there's not even any water.