About how many salmon from one spawning pair live from the time they're laid to the time they return as adults?
Each female salmon can have between 1,500 and 10,000 eggs. Only a few (0 to 10) of these eggs will survive to be adult salmon. A population maintaining its size only produces one adult from each parent on average (two adults from each spawning pair), but it will be higher in some years and lower in others.
https://wfrc.usgs.gov/outreach/salmon.html

Lets say 2000 smolt make it to the salt, the survival rate is piss poor.
I would say the impact of sportsmen is minimal compared to a gill net.
If we are talking about ESA listed Salmon and 10 Salmon make it back to the river 5 get caught in a gill net it is 1000 percent more impactful than an encounter with a Smolt.
Encounters in the salt with smolt are given too much value.

Yes this is junk science, not the reality of smolt mortality but the impact of smolt mortality resulting from encounters by the only user group that fishes selectively.