I don't see why you cannot add interactivity later on. Frameworks like VueJS provide an easy way to deliver interactive widgets on a subset of rendered pages of

I don't see why you cannot add interactivity later on. Frameworks like VueJS provide an easy way to deliver interactive widgets on a subset of rendered pages of a traditional website. If you need an API on the backend, you need to write that API one way or another anyway. This way people who are just looking for some information on a website can go visit, get, and leave, without having to enable intrusive JS blobs, while those in for the interative things on the website can get their preferred experience as well. Instead many websites are developed with only the second group in mind, often intentionally forcing you to run their code on your computer, or not delivering useful information at all.