If this was actually true, there wouldn't be so many people from the developed world trying to immigrate to the US, and upset about the US government making this harder.
That just means the US is better than the place they’re moving from. It doesn’t mean the US is among the best places in the world. Also, public perception of how good things are through US media (Hollywood) is different from reality.
Many, many people immigrate for an imagination of what life in the US will be. Objectively speaking, the US really is far behind most of the developed world in standards of living .
Also, money. Salaries are simply higher in the US (even if life is worse and less fulfilling overall)
I'm an American currently living in the Philippines, and that's utter nonsense and I know it. Developing world countries are so far behind the US in infrastructure, clean water, food quality, pollution, overpopulation, waste disposal, cleanliness, littering, open public spaces, and numerous other vectors that your comment blithely ignores.
The only possible way you could write a comment like that with a straight face is that you've never walked through a barrio in a developing world country with brick block contruction and tin roofs with tires holding the roof on, or favelas in Brazil with crowding, unsanitary conditions and resulting disease, drug crime, and gang warfare.
The standard of living in the US is vastly better than in these third-world shitholes, and it requires a stunning amount of out-of-touch suicidal empathy to project that it doesn't.
The US is not "behind the developed world", it's literally the developed world. The lightbulb. The airplane. The telephone. NASA. Space X. Tesla. And on and on...
When people talk about being behind or ahead the developed world, they are talking about the average person's availability of food, housing, internet, AC, transportation, healthcare, education, culture, day to day life, etc. Not century+ old tech or the handful of Billionaires' pet projects. Or, well, really, most of the time people just mean "The US is not like a subset of European (Likely Nordic) countries".
But that's besides the point, because I'm not the person making the argument. I was just pointing out that the comment was misread and misresponded to.