Swiss people learn English in school. I have only met a few who cannot speak English well. It's a much more common issue that I want to speak German with them, but they don't actually like German (it's something of a foreign language too compared to dialect), and they prefer to practice their English with me. Linguistic tugs of war are always awkward.
I fully agree with you, I was at a beginner's level on that occasion. Yes, if you are conversational then it's not going to change much (from your original post it seemed you barely spoke German)
And yes, the way to progress from conversational to the upper levels is mainly through classes
> but they don't actually like German (it's something of a foreign language too compared to dialect)
Ah that's true. Nobody speaks Hochdeutsch on everyday life. And Schweizerdeutsch is weird
> your opportunities to practice are limited
I spent 1 weekend in Zurich. I had a lot of opportunities to practice, falling back to English only when needed.
Then I went to Germany for a bit and again had endless opportunities to practice.
You still have to deal with eating, shopping, renting a place, going to a doctor, etc.
If the first thing that comes out of your mouth is "English, bitte?", yeah, you're not learning anything.
And the other foreigners there? Some have better German than English. They also want to learn.