What actually happens is behind these agreements are a team of people with an onshore presence and the actual employees overseeing the on/offshore work prefer to work with the same set of people. Once you get a team and rhythm going on work, it made things easier to predict. So both sides want to game this 'services contract' to have the same team for literally years.
If they make corporations count all of the on/offshore people as contractual labor in their accounting practices, which is what they actually are, then companies will be hit negatively in their P&L statements. These are essentially jobs which used to be done onshore so they certainly weren't 'talent can't be found' types of roles.