Power of veto
A few days ago we were preparing for a presentation to students of a masters degree in design, and in our preparation, a question came up: "what's the role of the designer in our particular team?"
I would argue that in most startups and consulting companies these days - particularly those with a limited headcount -, the main role of the designer should be that of curating/vetoing ideas. This is particularly true when working in an agile environment when everyone takes responsibility for crafting features and deploying code. In such a team, the development process is probably going to flow better if decisions regarding the experience and UI are consulted with the designer rather than always going through him. In short: developers work higher in the stack (they are expected to deliver interface work), and the designer is able to cover more ground and have a curation role across the project as a whole.
In smaller teams there's little room for someone that only does design, just as there's typically little room for an engineer who can only do one particular thing. So, playing on everyone's strengths by empowering engineers to deliver code top to bottom, and applying design expertise as a curation tool sounds like a way to optimize a company's process. Less time lost in waterfall is never a bad thing.