Remote-hosted agents are available in most places. BUT they are not interesting, because they do not have access to all the user's data.

People really want to run agents on their data.

Re sandboxing: I dont know Goldman's particulars, but most enterprises lock down all sandboxing tech on workstations. So I assume this is actually harder than it seems. So people just run it directly on the machine.

The article is referring to the dilemma of the trifecta twice.