You're right about the copycat behavior. This goes all the way to top of funnel: these small, even trivial-scale web application startups just don't have hard engineering problems. Many imagine they do, or imagine they will once they take off, but the work they're offering these high powered candidates they claim to want to hire is like, wiring up CRUD apps and making javascript buttons. It's not technically deep work, it's product work. A little humility about whether or not your tech startup is truly doing "tech" problems would, I think, fix some of the expectation/reality mismatch people are having when they complain about how hard it is to hire engineers.
And sure, lots of people join Google to work on world-scale problems and end up wiring CRUD stuff anyway. But they can at least plausibly offer some technical depth (or could anyway, perhaps Google's reputation as a great place to develop an engineering career has been fading).
(this is not to knock on "CRUD" but to highlight that a technical problem solver is an overlapping but not identical skillset to someone who can work with a fast moving team to quickly and reliably develop product changes)