Webforms version of asp.net always sypported this idea through soething called UpdatePanel

https://msdn.microsoft.com/en-us/library/bb399001.aspx

Commercial control providers in .Net world support these scenario with something called "CallbackPanel".

https://demos.devexpress.com/MVCxMultiUseExtensionsDemos/Cal...

Real conufsion starts when you have nested HTML controls that automagcally making ajax calls. Nice idea as long as you can get away with minimal work.

The moment you want to use any moden SPA framework, you are up for a big rewrite.