Not startups. 100k is like 75% of base comp in most bay area startups
Among BigTech, maybe like ~20 companies will be willing to pay this per employee.
I dont know of a single person here on a visa making less than 150k salary. They get the same stock, bonus and benefits that every one else gets.... it's well over 300k to have that staff member when all is said and done.
You're not adding on 100k a year, you're adding on 100k for a 3-6 year employee.
Even if that works out to 20k a year, it's pocket change in the grand scheme of things.
Don't have data on this but anecdotally the base salary range for most YC startup jobs advertised here is around 150k-200k based on what I see.
You are right that it does amortize if the employee stays long enough.
And I expect workers on H-1B change jobs much less frequently than citizens & green card holders (and holders of "safer" visas), since changing jobs on an H-1B involves more risk that can end up with you being required to leave the US.