Spray foam is the most expensive way to get R-value. Unless you have space constraints, or existing air sealing concerns, you should not use spray foam.

Cheapest is double stud construction + blown in.

It makes sense that the asbestos stuff would be required for a building that has asbestos. Improper remediation can cause harms outside of your property.

The R-value also makes sense IMO. "You can't build houses that aren't properly insulated" is probably a net good -- although only if the insulation level makes sense for the region. If it's too high, I agree with you.

I don't think it's fair to complain about the cost of solar if it's not required.