U.S.-based companies WILL NOT hire W-2 employees overseas, unless those companies already have a presence in a specific country (and usually city), and the employee also lives in that country (and city).

Tax liability is the main reason this is true.

The other factor you need to track is contract (1099/corp-to-corp) gigs. In this case, the contractor is taking on the tax liability himself/herself.

"Digital nomad" in Spain, here.