Maybe there is this disconnect, but half of the react developers I personally met used react: "because it is good on resumes and I don't understand how to work without a framework". So I am not entirely sure we have the whole picture here.

I also write more complex webapps using vanilla webtech (with a strong server-side solution like flask, django or similar). I checked out react it just hasn't clicked yet for me in combination with my serverside style.