first of all, you never HAVE to hold a tx. The fact you see it early already gives you the advantage (unless a crank arb bot gets lucky) -- the amount of profitable crank bots would also decrease if more stake would backrun :p
I also highly doubt anyone is holding transactions (even for just a few ms). They simply submit their arb in a bundle with the backrunnable tx. That is just jito / harmonic doing it's job. And for the 0 prio fee ones, it's likely just a private way of inclusion that skips the regular fee auction.
@eightbitsim@solana@Helius Sure, but is it someone right to land just because theyโre high paying and efficient? The only reason a validator would take a deal like this, is if they earn more than theyโd make on priority fees for those same opportunities