So just doing some cursory research - and I admit, I'm not Swedish - 67% seems to be on the high side as far as EMTR estimates go. So I think you'd need to make a pretty hefty amount of money in Sweden to pay that much. Wikipedia, for instance, claims that the EMTR for an income of over 675 000 SEK is only 60%; Glassdoor tells me the average software engineer in Stockholm makes ~500 000 SEK (though Glassdoor estimates can be questionable).

I bring this up because I don't think taxation has much to do with this. In NYC I was paying around 50% of my income towards taxes (federal, state, and local); when you factor in what I was paying towards things that the Swedish social system provides, I'm sure it amounted to very close to 60% (maybe even more!). But NYC is full of plenty of engineers or similarly well-paid professionals who've achieved financial independence. And, well, at least per Glassdoor (caveat emptor), the average software engineer gets paid literally twice as much in NYC than in Stockholm. IMO that probably has more to do with it.