What does overindexing on the swe market mean?

If these other professions don’t pay as much as swe, then doesn’t that indicate that domestic supply is meeting those industries needs better than it is swe?

Not at all. Salaries aren't just a function of talent availability, they're also a function of capital availability.

or it doesn't have software like margins so you can't pay insane salaries and you still need great talent that's not available in us (those salaries might be higher than normal but it won't match swe salaries)