You mean most Redditors live in a country with a higher GDP than 90% of people on Earth. That doesn't necessarily translate into 'significantly better lives', especially in a country with wealth gaps such as the USA has.
It isn't necessary to identify the world's most unfortunate person to recognize that most redditors have privileged lives, yet choose to wallow in misery.
This is not the 1950s. Most American's have internet, where they can see average people living lives around the world. Their houses may be a bit worse, but their cars are normally newer, they have internet, they have FAMILY. They have vibrant COMMUNITY. They have free time.
More like the super rich have huge influence over politics and can buy media companies to push their preferred narrative. Elon being the most visible example.
I'm not a member of the richest most powerful group of people ever, and my government falls far short of the ideal I envision, therefore I cannot possibly enjoy my life.
See, that's just using the same measuring rod. If you measure quality of life by income, yes, even poor Americans live good lives compared to the rest of the world.
There are many other factors you could evaluate it on, though, and many of them are harder to quantify. Stuff like personal agency, status, leisure time, social life, community cohesion, etc.
Life is bleak if you perceive it to be bleak.