Aside from giving talks and maybe event organization, the rest of those functions (docs, tutorials) already have roles.
The more naked truth is here:
> marketing teams usually don't have the technical knowledge required
DevRel is marketing that targets developers. They do all the things marketers do: drive adoption, control perception, pressure product teams in customer orgs, and drive product-market fit.
Just like marketers try to build champions in C-suites and pursestring-holders for sales to use to land and expand, devrel builds champions on dev teams in orgs where devs have more control or influence over budgets.