The whole subject of modality in design is a long story but the short story is that we should not mistake the need for ease of implementation with the need for

The whole subject of modality in design is a long story but the short story is that we should not mistake the need for ease of implementation with the need for clarity of design. They are orthogonal. There is no question that a design gets easier to parse for users when it is serialized by modality. Likewise, serialization is dramatically easier for implementors since it eliminates the need for concurrent execution. Context matters. Those choices have strong historical reasons for their existence in operating systems and their user interfaces. However, they have little place for being emulated on the web. Why? Because they give rise to all manner of bad implementation such as the fact that linking structures have not grown at the pace they should have, particularly as it relates to documentation. All you have to do is look at Amazon's constant proxy to "click here, click there" as a sad excuse for why HCIs don't scale at the same rate as APIs and you can condemn a large portion of the last two decades of design on the internet since these patterns have been copied ad nauseum but only exist because we've employed tools that automated their creation when a link has always been worth a thousand words of "click here, click there". REST applies to HCIs as much or more than APIs.