Why are interviews harder than the job?

Jm2c but interviews tell you absolutely none, nothing, about what kind of a professional the candidate is.

I have no clue whether he'll care and help or pretend to work and drag everybody else down.

There's a huge number of incredibly capable developers who could pass any interview but then spend days playing video games and sabotaging projects and teams.

I really don't believe in technical interviews, I'd rather base the relationship on trust, if you tell me you're good/experienced at X I trust you to be. If it was bs you'll be shown the door with ease.

Instead many companies make it insanely hard to get you hired, but also incredibly hard to cut you out even if you're impact is a very net negative.

This works very well for contractors, less so for full-time employees. You can't just fire somebody on a whim, at least not for free, not even in the US, let alone in most of Europe.

To be clear, I'm not saying worker protections are bad, just that if firing is much more expensive than hiring, you can't really afford to hire any warm body that walks through the door. These days everyone and their mother is in CS, there are many more talented people than ever, but also more duds than ever.