In the case of fish ladders, the fish that succeed transit the ladder by themselves.
From the video it seems fairly labor intensive having to stuff all the fish into the tube. In one scene of the video it appears that that the fish have been cleaned and packed in ice before launching, so you have to add in the labor to do that as well.
For the run and dump alternative, finding more (ahem) fit runners might improve the throughput. You could even market the activity as a fitness regimen. You get the aerobic workout of running back and forth along with the upper body workout of carrying and throwing a big weight around. In addition, you get the satisfaction of contributing to the success of the salmon migration instead of merely swinging some hunk of metal around in some gym someplace. You might even be able to people to pay for the privilege of doing so.
