That in no way hinders your ability to use automatic translation tools (also AI-powered Aria, built-in into Opera browser) to read the contents in foreign languages. What's more - if you don't know English you can use these tools to help you write a post, too. And that's a proper way to use AI in this context, I think.

On the other hand, allowing everyone to post everywhere in a language of their liking would unfortunately, in my opinion, among a few other problems, do just the opposite of what you are after - it would create rather than overcome language barriers, because it would force the people in the discussion to rely on the translation tools all the time. Their quality vary and it's quite possible that some people would be able to understand what the person writing in other language meant, but others (that happen to have used a translator that was not up to the challenge) would not. It would be very hard to have a real discussion in such scenario and misunderstandings would, inevitably, follow.

Having all the forums content in English makes it relatively accessible to people that don't understand it. Having it in a plethora of languages, some of which are less popular (therefore translations from it would lack quality), would make it less, not more, accessible for everyone.

Maybe in the future we'll get there, though

I strongly believe the language barrier should be overcome rather than enhanced, with the current translation services tools (not to mention AI) that are already available.

Goede dag! Now, before you get too excited, you have just read about half of my entire vocabulary, the balance being: (of course) alstublieft. I am a Canadian senior who was fortunate enough to spend three years in your gorgeous country, back when in my mid-teens. Ever heard of Klimmen or Valkenburgh ?

I have created a Dutch local forum for you
https://forums.opera.com/category/65/nederlands