Regardless of how many fish one kills, that fish won't spawn. If, as is normally the case, the harvestable surplus is taken certainly outside the tributaries if not outside the river then those dead fish eat into the escapement goal. It's a numbers game.

Certainly nets can and generally do take more fish in a day than any one angler does. Look how fast the Lake WA sockeye anglers take fish out whenever there is a fishery. A fishery that was historically inefficient enough to last months now (when open) lasts days.

Volume-wise, the problem for WA Chinook is AK and BC; no argument there. But WA anglers can and do remove enough fish to impact escapement. Dead fish don't spawn.