VPN adds an average of 100ms of latency to the existing constants in the network, so if sites are connected by VPNs, and then you implement additional VPNs for each PC to connect to a server, it quickly mounts up.

Optimizing your budget and adding capacity systematically for maximum application efficiency is vital to network planning. Too many times, we’ve seen businesses adding capacity and spending their money on bandwidth when other, simpler changes (like endpoints too far apart) could provide an easier (and cheaper) solution. 

Modern network technology is a marvelous thing, but sooner or later, it always comes up against the immutable laws of physics. Even fiber-optic networks are limited by the speed of light. If your endpoints are at opposite ends of the Earth, it’s physically impossible to transfer data between them as quickly as you would two endpoints in the same building.

There are also several applications where latency’s effects have limited impact. These include Customer Relationship Management (CRM) platforms, productivity tools like Office 365 or Google Workspace, E-commerce platforms, and billing or audit tools.

More info: Windows 10 Office 365 Migration Services