As this comes close to what I think is an important point, I will briefly(?) rejoin the discussion.
I agree that “human reason is nowhere close to explaining everything adequately”. And it’s arguably the case that atheists/agnostics find themselves with fewer “adequate” explanations by virtue of the fact that faith-based beliefs are effectively out of bounds. Yet every day we all have to make decisions on how to act based on what explanations we have. Each of us may be pretty confident in some of our explanations, but others fade much more toward being just best guesses. Still, we have to live our lives making decisions as best we can based on what (we think) we know. This is better characterized as a matter of necessity rather than of faith.
I’ll readily concede that it’s possible to sometimes make good choices using faulty reasoning, but suggest that people who make decisions based on more complete and accurate explanations are generally happier with the results.
Our decision-making is where “the rubber meets the road” in determining the usefulness (truth?) of explanations each of us decides to accept.
It seems to me that atheists/agnostics are more comfortable acknowledging the shortcoming of our explanations (i.e. “I don’t know”, and have a hard time understanding why anyone would rather leap to unsubstantiated faith-based (unquestionably true) explanations with their potential for leading those believers into making decisions that work out less well.
My two (Vulcan?) cents…
I'd characterize it as "necessary faith".
As for the complete and accurate explanations, perhaps but there's a point of diminishing returns. A complete and accurate explanation on the functioning of the human body for any given second would be staggeringly long and somewhat beyond human knowledge. Everyone draws a line at some point.
I agree with your last point that logical explanations and acknowledging our shortcomings usually end up with objectively better results, but human life is not so cut-and-dry. Say someone has been brought up in a religious household and prayed since they were 2. Say, for whatever trick of the universe, 90% of their prayers come true, including some of the heavy-hitters (family problems, financial issues, etc). By the logic of producing good outcomes, regardless of whether it's objectively true or false something that produced a 90% success rate is worth hanging onto.
As for happier, I'm sure some Atheists/Agnostics are, but I know plenty who are far more miserable than my religious friends. Sure some of that is likely to be "ignorance is bliss", but to twist Atheist logic on itself for a bit: Atheists are all about acknowledging shortcomings in human reasoning. What if a human shortcoming is that recognizing those shortcomings makes the average person miserable, less productive, and driven to make worse decisions?
Or put another way, who's more honest? The Atheist, or the person who acknowledges their religion is unproven but believes it anyway and is happier/more productive for it? I'd say they're both equally honest overall. On the flip side you have people who will claim that they can logically prove Jesus literally walked on water and you have Atheists who are nothing more than miserable, angsty teenagers raging against religious parents. At the end of the day it's all based on personality type IMHO. Everyone needs faith of some variety, but some need more or different types than others.
For my part, if faith of whatever variety makes someone happy and a positive member of the community, and dislodging that faith would decrease that effect, why dislodge it? Perhaps the objective truth is less meaningful to that person, and might even damage them. In that case convincing this person of that objective truth would be a purely selfish and potentially damaging action.