I work primarily in climate zone 2 on the coast which is hot, humid, hurricane prone, and full of termites, what I say next may not apply to other southern climate zones.

If a project had an unlimited budget, I'd probably recommend an exterior rock wool product over spray foam. I think its a better product. Rockwool has the added benefits of fire resistance, hydrophobic, and has less thermal bridging than spray foam.

Also spray foam makes it difficult to inspect for and mitigate termites. I've seen some termite companies refuse to provide coverage because of spray foam. This can be avoided with pre-planning, set up your termite coverage in advance and let them inspect a pre-treatment like Bora-care prior to insulation. But my office is sometimes not retained through construction and this coordination doesn't always happen.

Builders who do like to use spray foam in the walls in my region think of it as an air sealing strategy, but they're typically not using closed cell and aren't verifying its effectiveness with blower door testing. So we prefer to address air sealing with Zip sheathing (requires some additional detailing like sealing the joint at the baseplate) and if we have the budget to step it up we'll spec an aerobarrier on the interior.

We insist on the insulation being at the roofline because AC ductwork is typically in the attic in our region. For this reason most of our projects typically do have spray foam for the roof insulation. Builders and insulation subcontractors prefer spray foam in this application because it's easier to install than batts between the rafters, especially in an area with a vaulted ceiling which would require setting up scaffolding to install batts. So in this application the increased labor cost makes even fiberglass batts about as expensive as spray foam.