So two questions here:

Considering ALL the trade-offs, which places are really, truly plainly better places to live than the United States?

I haven't been to the United States since 1999. However I have been to a lot of other places, some good, some bad and I can honestly say that most of Canada seems to be fine, albeit a little colder than most of the US. The UK (although I'm biased, as I live here) has a lot to offer while still being culturally close enough to the US. Australia is a wonderful country far better than most, but culturally somewhat coarser than the US. New Zealand is also good and slightly more reserved than Australia.

Outside of that I've had good experiences in the Netherlands (lots of English spoken too if languages aren't your thing), Spain, France and Turkey (aside from the actual bombings that happen relatively often without the government losing it's shit, but then the government losing it's shit and doing stupid stuff like trying to block youtube). I would say that Greece is probably not a good place to go right now which is a shame as it's a lovely place.

Australia and Turkey both have fairly good economies, Canada's not doing too badly either on that front. The UK has a thriving tech/hacker community in most major cities and while the economy is shaky London's still a great place in Europe to launch a startup.

Which places are better to visit for tourism?

Again, I only have limited experience of America and it's caught in a bubble from two decades ago. My memories of America are incredibly friendly, wonderful people, good service in restaurants, everything being too big (from portion sizes to highways to the distances between things) and some really impressive modern art and culture.

Canada I'd highly recommend but it isn't that different (although Montreal is wonderful and Vancouver is great too, although I've never been to Seattle so I don't know how similar it is). Anywhere you go in Europe you're going to find history, art and all kinds of stuff.

The UK is a great place for Americans to go on holiday, as is France, Germany, the Netherlands, Belgium, Spain and Italy. London and Edinburgh offer a host of things to see and do, and places like the Brecon Beacons offer the most amazing walks.

If you were to go to Istanbul I promise you an experience unlike anything you will have ever seen, heard, smelt or tasted in a 3,000 year old city that's seen earthquakes, ransackings, churches, minarets and wars over time.

The catacombs in Paris are really something else, although I always tell people to ditch the Louvre and head to Montmartre for fine French culture from la belle epoque.

Bavaria has the most amazing mountain air and there's a whole load of beautiful walks through Ludwig II's old garden, not to mention the beer and food.

Andalucia in Spain offers incredible history, art, food and fiesta from bullfighting and tapas in Seville to the Mesquita in Cordoba and the Al Hambra in Granada. Barcelona is one of the most laid back beautiful cities I've ever seen with wonderful people.

Of course all this is academic. You asked a set of questions at best seeking validation that the US is the best place in the world or an opportunity to challenge it. If I hadn't made a conscious decision not to go to the US while the DHS and TSA still stand (foolishly believing it'd all be sorted out in a few years) then I wouldn't have seen half of these places. Sure I'd have seen New York, Vegas, LA and maybe a few other places but would I trade that for Paris, Barcelona and London? Tough call to make, each to their own I guess.