You said it yourself. The market for new grads is bad. AI is better for senior employees than juniors. Visas don't affect this dynamic.
But a contributing fact is flooding the tech market with H-1B visas spikes labor supply, kills workers' leverage and lets companies cheap out on salaries instead of bidding them up.
The imported worker, on the other hand, is a more efficient and compliant machine. Maybe if we make those youths as poor as the workers we import, they'll eventually learn some gratitude.