Greasy Fork

There is an API in Google Translate without token.

fetch(`https://translate.googleapis.com/translate_a/single?client=gtx&sl=auto&tl=${localeLang}&dj=1&dt=t&dt=rm&q=${q}`)
                    .then(res => {
                        return res.json()
                    })
                    .then(result => {
                        let resultText = result.sentences.map((function (s) {
                            return "trans" in s ? s.trans : "";
                        })).join("")
                        return resultText.split("\n");
                    }).then(result=>{ console.log(result) })

The developers do not need to translate the content into every language, and GreasyFork can just store those translations during publish or update of the script.

This is similar to what Google Play Store does for Android apps. The users can always see the translated descriptions of the apps if the locale is not typed by the developer.

Took this as an Example: https://greasyfork.org/en/scripts/455261-xbox-cloud-gaming-region-unlocker

Xbox Cloud Gaming Region Unlocker
Unlock Xbox Cloud Gaming region restrictions.
Support manual selection of game versions for different regions (some games lock language according to region), selection of region does not affect the server connected, the server always automatically selects the lowest latency.

There is no español version in developer's typing.

Then it can use the API to auto-translate (during publish & update) The auto-translation can be done by user-side JavaScript (i.e. the developer's browser)

The developers do not need to translate the content into every language, and GreasyFork can just store those translations during publish or update of the script.

I disagree, there may be some specific texts that shouldn't be translated, you can't just tell the Google Translate not to translate some particular text. For example, let's take my user-script "Greasy Fork Dark Theme", obviously "Greasy Fork" part shouldn't be translated, but Google Translate can't understand it.

But if you really want users to have translation, then just create a user-script to translate name, description etc. I don't see any problems in it.

I leave it up to authors to decide whether and how to provide translated versions. I would prefer not to automatically translate content as the result can be poor quality.