[mschuster91]

There are distinct advantages of client-side rendering, but it depends on usage patterns.

One case is you're something like Reddit, Facebook or Twitter: the transformation logic (i.e. JSON-to-HTML) is cheap in bandwidth to send once and have the client re-use it countless times. Bonus point, you can re-use the backend code for various frontends (web app, native iOS/Android/... app, Electron app).

The second case is anything that has a large number of one-time visitors: delivery of the transformation logic can be done using a cheap (and visitor-local) CDN, and you only need to scale the backend servers according to load - and you only need to pay for this task, as the computational cost is outsourced to the visitors.

The case where server-side rendering shines however is infrequently visited sites or ones that don't have external or internal interfaces, like a company's or personal blog or homepage: there, the effort required to maintain complex logic on both server and client is greater than just throwing up Wordpress.

[JohnFen]

You're listing the benefits for the website, and you're right -- those benefits are why sites do this.

But what it's really doing is lightening the burden on the server by increasing the burden on the client. There is little benefit to your readership. And allowing client-side scripts also decreases security and privacy.