I will admit that I don't know regulations outside of my area, and I'm guilty of assuming they are somewhat standardized across the US (and indeed, for some codes, internationally).

Here we just have city inspectors to check basic code compliance. They'll take a quick look at the framing, electrical, and plumbing before the sheetrock goes up, and then they come back for a walk-through before issuing the certificate of occupation. No engineers.

The biggest fees by far are the permit fees, but that's for revenue and would still exist if engineers were doing the analysis for the construction.