With Agile methodology, it is apparent that what can be achieved by developers remotely not only costs less than onsite developers but may be more productive. Developers tend to be motivated by technical achievements and learning, and being remote but dedicated to a specific project with focus, using modern communication methods, can actually result in faster and a higher quality of work. Peer review is essential.
See also https://www.inc.com/brian-de-haaff/3-ways-remote-workers-outperform-office-workers.html