Banking revenue is 7-9% of Swiss GDP, on par with many industrial nations. Commoditie Trades are disproportionate to Switzerland’s size for sure, but I fail to see how that translates to salaries in McDonalds - their main target market is hardly bankers and commodity traders. I think it has much more to do with the social safety net which imposes an implicit minimal wage (companies have to offer something significantly above what one can get from the government).