Not quite. instead of a bundled pinned version of electron, it is an arbitrary version of edge's WebKit fork shared across all programs using it. That means you don't need to keep multiple copies of the webkit libraries loaded into memory.

That's not to say that building things on web technology is an efficient use of resources. Even if multiple programs are sharing the webview2 library, they're still dealing with the fundamental performance and memory problems caused by building an app in JavaScript.

As for why teams is so memory hungry? I would blame Teams.

Discord manages to make a half decent, highly responsive webview app, and that's with the overhead of having its own separate instance of electron.

EDIT: the original poster was also talking about application binary size, not runtime memory consumption. Application binary size should actually be significantly helped by linking webview to instead of bundling electron.