The cost of living in my country is actually cheaper compared to other countries yet it's still hard for a local citizen in my country to survive for everyday living. Others might find it cheap but an average person here finds it difficult to manage daily expenses. According to the data, an inexpensive meal here costs around 4$ while in the US it's 20$ which is very cheap when you compare yet some can't even afford to eat 3x a day.
Every country people have such scenario, USA is not an exception. Same as other countries USA too has got people who can't afford three time meals. From outside it looks like so luxurious, but in reality USA too lacks. But, they try to hide it to the world. This might damage their value as the world's power. There are people in USA who live their entire life on vehicles just because they aren't able to afford the house rentals.
Comparing cost of lives blindly isn't correct, you have to consider a lot, really a lot of things. How easily can person from other country start job there, how are other people accepted there, what's common and average salary there and etc. For example average salary in one country is 150£ while in UK it's £2000, then 300% difference between cost of lives according to calculator that OP used, gives us absolutely useless information. Without doubt UK is a great choice.
the cost of living of each person is certainly different, we cannot compare it with others. and of course the cost of living in each region is different. because every city has different political and economic policies. so I don't think we need to compare our living costs with other people's living costs. what is important is that we can meet the cost of our lives and live happily I think that's enough.
I don't agree with you too, we have to compare. If there are issues with us, we need to fix it for our better future. Imagine yourself in 16th century as an imperator, you would may be one of the most happiest person as an imperator but also remember current situation: Imperator where you have no electricity, pc, smartphone and etc or current one with this opportunities? They don't had request on such things, haven't seen such thing and were happy with that way but now when you saw better things, you won't feel happy without them while they would because haven't seen.