Have you ever lived in an actual third world country? Here’s some from my home country for each of your examples:

• Corruption in government is worse and more blatant than what you see in the US. It happens at the top all the way down to the lowest levels. You sometimes have to bribe people just to get some services done. I once had to have a police report done for an auto accident. The officer had the report typed up and they just needed to click the print button. He then said I can pay a quick process “fee” to get the report now, or come back to get the report in 3 days. It was an hour drive to the station, but I didn’t want to pay a bribe, so I came back after 3 days.

• Infrastructure is crumbling not just because of lack of maintenance, but because the cheapest materials are used and infrastructure is not built up to code. Every step of the process means a cut for someone’s own pockets, so you end up with a tiny amount compared to what was initially funded. Perfectly functioning roads are destroyed and rebuilt in perpetuity because contractors are in cahoots with local government to implement “projects” where they fleece funds by agreeing on a budget then switching materials to substandard quality and pocketing the remaining amount, with the politician getting a % of course. A section of the street in my childhood home is still unpaved 30+ years later just because no one bothered to finish it.

• Homeless people in the US may still have access to food banks, shelters, charities, etc. Homeless people in thrid world countries may have nothing at all.

• People lose power in the US due to catastrophies. We had random 12 hour blackouts and water shut-offs several times a month for no reason at all. Water isn’t potable in the entire country and you have to boil or buy water from filter stations if you want to be safe.

1.2. and 3. worlds are terms from the cold war.

https://en.m.wikipedia.org/wiki/Three-world_model

Third World is an outdated term to refer to neutral countries in the cold war.

Unless there was a sudden dramatic shift in US geopolitical policy it would literally be impossible for it to be considered third world, as the very definition of third world as the definition inherently implies that the country in question is not allied with the US and the broader Western World.

Austria and Switzerland were third world, technically Yugoslavia was too. China became third world for a decent stretch after the sino-soviet split since the other half of the definition relies on not being allied with the Soviets in particular.

The use of third world as an insult for poor countries is a neo-colonial mindset that just takes for granted that anyone who isn't an outright ally of the west or of the Russians must just be too poor to be worth considering as anything but uneducated people in dirt houses living subsistence lifestyles and who's main interaction with an apparatus of state is occasionally seeing a humvee loaded up with the child soldiers of this warlord or that drive by.

Because "first world" means NATO, not having a high standard of living.

Because the actual definition of a 3rd world country doesn't define the USA as one...that's why. You're adding things that don't fall into the definition.

If you mean “developped” vs “develloping”.

The HDI of the US is significantly lower than canada or northern europe, but still much higher than the world average.

Here’s an Inequality Adjusted version of the Human Development index, the US comes 27th, below Estonia and Cyprus, but 27th out of nearly 200 is counted as “develloped”.

https://en.m.wikipedia.org/w/index.php?title=List_of_countries_by_inequality-adjusted_Human_Development_Index&diffonly=true

Because the definition of "first world" is "aligned with the US during the Cold War", second world was aligned with the USSR, third world were countries not significant on the global stage. It correlates with but does not require poverty or dictatorships.

Several reasons.

1. The US is largely responsible for defining what 1st, 2nd, and 3rd World countries are.
2. It has the largest economy in the world.
   (I think? That may have gone to China by now. Not sure. But it was true recently.)
3. Even with everything you said being true. It's still the wealthiest country in the world, by a large margin. Epically when you compare incomes, lifestyles, and infrastructure to actual 3rd world countries. It's not even close.

Because the "third world" doesn't mean what people think it means. It's cold war terminology. First World is western aligned nations, Second World is Eastern bloc, Third World is nonaligned with the eastern or western nations. FBFW it meant nations that generally weren't powerful or wealthy enough to be of interest to either East or West, and that poverty often meant they really had a lot of infrastructure and other problems. That's why we're not "Third World", it's a geopolitical alignment, not a quality of how we treat our citizens and infrastructure. So we're First World even if our country is turning into a shithole in some ways.

Because of their GDP. People are incredibly rich there. But one false move and there are no safety nets. You can get bankrupt in an instant.

Where are you getting this from?

Because of very high GDP per capita. It's another discussion whether GDP is a reliable measure of economy output.

The Gucci belt

https://digitallibrary.un.org/record/1629536?v=pdf UN report from 2018 so pre-pandemic.