According to Wikipedia,
https://en.wikipedia.org/wiki/Languages_of_Switzerland
French is spoken by 22.9% of the Swiss population, including regional French dialects.
Perhaps it would be worth translating your websites into German and possibly into Italian and English in the future?
From what I can see Swiss casinos are in English, French, German and Italian. Of which English happens to be the main one (but maybe it's geographic targeting because I don't access these sites from Switzerland)
If the website already has some authority, perhaps such a translation can quickly gain a good position in the search engine.
You can use DEEPL for translation, which when it comes to European languages is really great and often better than human translation.
I would do it first.