I mean, you have to have an .astro file if you want your route to be picked up, and then import and use React components in that file. IIRC, you cannot just directly use React.
Oh right, yeah I get what you're saying now. Indeed I think .astro templates make sense at the page level say to define a layout, and I actually like the syntax of stuffing the server js into a frontmatter style block, it's pretty nice.