I agree with all you've said here, first of all.

> Many startups want Senior Engineers with several years of experience

This is often advertised. It's sometimes listed as a requirement. Those requirements are more flexible than new grads ever realize.

I think, coming from school, it's easy to take those lists of requirements literally. It's quite common, though, to hire people who don't match the requirements exactly.

Something is probably improvable, there - job listings are written in a kind of code that's not obvious at all to new grads. You kind of need a few years of experience hiring people to understand what they even mean.