We work globally so practical things like timezones aren't really a factor; we have plenty of experience working around them. That even goes as far as things like personal security in locations that are particularly dangerous. In my line of work that usually means risk of kidnapping. It will be a factor we take into account but wouldn't usually be decisive.
Having said that, I have been involved in setting up multiple offices in new locations. But only where we're expecting to have a significant presence over the long term. Essentially, where we can amortise the costs of legal and tax expertise.
Source: reasonably senior executive at a very large, global financial organisation.
Having said this most companies I encounter that have overseas workforces set up local corporations where staff work in proper offices. We have a lot of customers so I see this a lot.
These that did not filter me that way, offered both: either regular employment or B2B. These are truly rare, say 2%-5%?
My guess is that in countries like US, B2B contracts for individual SWEs are considered something very special and snowflake'y. Like they fully expect you to disappear three hours in, never to be seen again.
many companies are afraid of the employment laws they don't fully understand
timezones/cultural differences
There are still contracts for working remotely at companies like this, but you've gotta be known for solving painful problems that they can't fix themselves