Is there any option if I want to do traditional (non JS) SSR but also want to share an API endpoint for both browser and other use cases?

Seems like a JS frontend framework or a JS SSR is the only option for such use case. If SSR and API force a JS backend that leaves a lot of the benefit that other languages bring to the table and effectively limiting you to 1 (JS) or 2 (TS including) languages. Seems like a sad state of affair in that regard.