Anyone being able to write here seems mostly to be an obstacle of scale. One-on-one support's not an option, but there are other ways.
Integrating some kind of spelling/grammar checker (Grammarly or something) into the writing space would be a good start.
Maybe some kind of optional, self-paced learning paths devoted to different elements of quality writing. I'm thinking about learning platforms like Udemy and Codecademy as examples there.
Also, some way for more experienced writers to mentor new writers that's built into the platform but isn't tied to the publication submission system.
I don't really know what would work or what's been tried. These are just some thoughts.