To expand on this point - you can build a site that both uses Angular and has a fallback to plain http methods. Forms can do full posts, links can actually link to things, etc. Angular doesn't preclude you from a progressively enhanced site - its's up to the developers using Angular (or any client-side framework) to build for plain server communication as a priority.

However, "Therefore there is no need for progressive enhancement" is also wrong - there is. That's why they use "title" for tooltips, a textarea for code boxes, etc.