I genuinely encourage you to follow that sense of wonder and look it up. The information exists out there, you just have read it yourself and not take mine or others interpretation of it as gospel.
As a retired research scientist I couldn't resist looking into this. So, using the Google Scholar search engine I searched for "hooking mortality" and got a number of good hits. The most relevant publication was from 2011, published by the American Fisheries Society, titled:
Determinants of Hooking Mortality in Freshwater Recreational Fisheries; a Quantitative Meta-Analysis. For those not familiar with the scientific literature, a meta-analysis is when researchers review multiple prior publications on a specific topic, compile, re-analyze and summarize the data and publish the findings.
This particular study was quite extensive, reviewing 107 prior hooking mortality studies (who woulda thought there were that many?) and extending for 30 pages. I focused on the results for the
Salmonidae species (trout and salmon) as that's what I fish for. The relevant conclusions for
Salmonidae state:
mortality caused by artificial angling baits (11.6%) was significantly lower compared to natural baits (27.0%). Within the salmonid family, hooking mortality did not vary with hook type (single vs. multiple) but average mortality of Salmonidae caught on barbed hooks (15.1%) was was significantly higher than for fish caught on barbless hooks (8.6%).
Regarding Wavesliders assertions we can conclude the following from this publication;
Barbless hooks alone reduce hooking mortality by about half.
Treble hooks are not more deadly than single hooks.
Bait does cause higher mortality than artificial lures, but only by about two-fold, not four-fold.
The publication did not address time out of water.
Regarding time out of water, since it is easier to remove a barbless hook than a barbed hook, it would be reasonable to assume that barbless hooks would reduce time out of water, so this may partly explain the reduced hooking mortality with barbless hooks.
The discussion about single vs treble and bait vs lure is moot for me as I live in Nevada. Nevada regulations for catch and release waters state:
artificial flies and lures with single barbless hooks only so that pretty much covers everything.