Have you considered that you might not be a fit for companies where you are applying? For example, I would bomb at any enterprisey company, and I do really well in small early stage startups.

I could apply to hundreds of corporate jobs and I'm pretty sure I'd get none of them. Whereas for small startups I have historically rejected more offers than I've taken.

In fact, I have never gotten an offer from any company bigger than 30 or so employees. And yet my inbox gets at least 1 recruiter spam per week.

But that's besides the point. If there are very many engineers out there who aren't getting jobs within, say, 1 year of actively starting to look. And if there are very many companies out there that can't hire engineers within, say, 1 year of actively starting to look. Then there's something wrong with market fluidity in one way or another.

That said, I don't think I've ever heard of a competent engineer who can't land a job within a year of actively seeking.

Then again, I've heard that if you aren't doing anything useful for over a year, your prospects start to dwindle because people wonder what's your deal and see it as a red flag.