Science is not particularly reliable.
And yet, we have remarkable technology, and can do medical marvels.
My tentative theory is that there's a lot of knowledge that's less formal than science in engineering, manufacturing, and the practice of medicine which makes it possible to get work done, and some fairly effective methods of filtering information that comes from science.
I expect that part of what I'm talking about is tacit knowledge, but I bet that some of it is explicit but localized knowledge. The knowledge (whether tacit or explicit) remains local partly because no one is interested in hearing about it-- too arcane for the lay public, too low status for scientists, partly because a lot of it is trade secrets and/or requires a security clearance, and partly because it's highly specific, which means it gets forgotten if a project or technology is abandoned.