What happens is, first, speed is still an issue because life and news do not happen on 1-second intervals. So readers will wait til as late as possible to make sure they have up to date info and then send their orders as late as possible.

Second is the risks to market makers goes up, which means they need to acquire more edge to cover that risk, which in turn widens the bid-ask spread, which makes prices for retail traders worse and will likely reduce liquidity as well.