What if we make the fee per-year? "It costs $10,000 to sponsor a new H1B immigrant's entry, and then it costs $5,000 per year per H-1B employee you have." H1-B holder is free to leave, and the cost of that happening to their employer is fairly low. Then let's say after 5 years of H1B employment, you automatically become eligible for citizenship, since you're clearly a valued worker.

That's what they're doing, it's going to be $100k per year to sponsor, up to 6 years.