The thing is, older jquery-based progressivly enhanced sites had a number of problems:
- You might have a page that was technically usable, but in practice terrible without JS – datepickers are the most common thing I can think of. In a typical jquery-type date-picker progressive enhancement situation, there’s a text input with a particular format you need to use, which is much mor epainful to use than a datepicker.
- As you move more logic into the client, maintenence and code orginization becomes a problem that traditional tools like jquery plugins just can’t solve.
- Accurate – the markup will be the same because it’s rendered by the same code
- Maintainable – one codebase, one rendering path
- Quickly rendering – we can use all the tricks of traditional html rendering sites to get the page to render fast