Honestly most of the time you can even just cut out the REST layer except where it overlaps with views by coincidence. For instance in practice there are quite a lot of views which simply get a single resource, or list a single type of resource with paging.
For mutations I am a big fan of just doing it RPC-style. I know it's not to everyone's taste but I feel like abstracting mutations out behind a model of RESTful resources and verbs is, 99% of the time, a waste of time, the notable edge case being where you truly need a flexible API for 3rd parties (both apps with UIs and scripts) where organising functionality in this completely generic flexible way - with the considerable extra effort that you mention being the price to pay - has huge payoff.
In my experience, it hasn't been the case: designing a REST API (I know REST complexifies the API compared to tailored RCP) that behaves properly for the client is magnitude more work than rendering HTML with data server-side.
The main difference is switching the question from "what does this page needs to render for this user", to "what are all the things the front-end might want to access through this API for this user, and how do the front-end plan on filtering". The former is obviously easier to answer, and as the result easier to code.