I was going to say somewhere in the mountains in Switzerland, but not the literally most busy city we have :)

What makes Zurich one of the best places to live now?

High standard of living, excellent infrastructure (transport, finance, biz, gov), very good education (ETHZ, UZH, ZHAW, etc.), surrounded by amazing nature and landscape, very open and diverse (30% foreigners, all shapes and colors), political stability (don't underestimate this when you're thinking about 2050) and solid governance by direct democracy (ZH/CH)... the list goes on and on.

To not "pollute" this comment with various links the simplest way to get a few reference points is https://en.wikipedia.org/wiki/Z%C3%BCrich

Of course nothing's perfect and there's always room for improvement (obviously), and Zurich is also a place with a very high "transparency of costs" so people pay for most of these benefits (less by taxes - but more by rent, cost of living, etc.) but to keep it short: Historically and with recent and future developments it seems to be a valid candidate for being a good if not best place to live in 2050...

Currywurst and Lindt chocolate

Not sure if that's a joke or reference i don't get but Currywurst is not Swiss (and honestly i haven't seen it here very often either) and Lindt is basically only the "cheap export stuff" you would be surprised how much better chocolate can get ;)

There is a Lindt factory in Zurich and there are plenty stands selling wurst and currywurst in Zurich

Ah, could have better argued with that. Excellent points! And don't forget the funny cheese and nice watches ;)

Try läderach chocolate