Jito's client runs on 95%+ of Solana's active stake; one provider operates the validator client, the relayer, and the block engine where ordering rules live.Flowra — led by Harry Hwang (ex-TradFi/CeFi quant; founder of block-builder Mevity) — is building an Open Orderflow Auction (OOA) plus Programmable Block Policy (PBP) as the open alternative.The counterintuitive core: exposing orderflow to many searchers compresses searcher margins, not validator revenue. Ethereum's PBS produced a measured +261% in proposer revenue.Compliance is built in: PBP enforces sanctions/AML screening and blocks single-bundle sandwich attacks at the infrastructure layer.The honest risk: open markets can re-concentrate — on Ethereum, the top three builders now win >95% of auctions.