I distinguish between web applications and thin clients. When I was in the business, a thin client meant you ran everything through one instance of Chrome, but today's web applications don't work that way. They each bring their own Chrome with them. It's much less memory efficient but allows them more control over what version is running their app. Also, many web app based applications still have special extensions to expose features Chrome normally wouldn't.

It's possible the terminology has changed over 10 years.