> from your explanation of the role I'm not sure I see the value either

Google has traditionally had a fair number of developer relations engineers. Chrome team alone has several. The current devrels include Una Kravets, Bramus van Damme, Rachel Andrew, possibly Jecelyn Yeen, Oliver Dunk, Matthias Rohmer, probably some others... They help prioritise new browser features through developer feedback, document new features, maintain documentation at web.dev, spec up new features and represent Google at various standardizing bodies, write walkthroughs and tutorials, build demos to showcase new browser features, make explanatory videos, give conference talks, and generally keep us, web developers, up to date with modern browser best practices.

Their value to web developers is immense. Their value to Google is possibly in that good devrels are a living advertisement of web technologies in general, and Chromium-based web browsers in particular. The better developers know browser features, the more attractive and capable UIs they can build for the web, the more consumers will be attracted to the web (including Chrome), and the more money Google will ultimately make via advertisements.

Adam has been so great in this role that it does not make sense to me that Google decided to cut specifically his position.