There are an ass load of reasons:
- Wealth- The US is extremely rich. We make up more than 25% of the entire world's GDP. In other words, we have more than a quarter of all the wealth in the world.
- Innovation- The US is a leader in this field. Think of all the stuff we invented in the 21st century:
-The assembly line
-metal water vessels
-put a man on the moon
-the cell phone
-Military Power- Our military is incredibly overwhelming. Our military expenidture is more than the rest of the world combined. Everything from our training, to weapons, to clothing, to vests, to gear, to tanks, to vehicles cannot be matched. Other countries rely on us such as the UK, Canada, China to export weapons, tactics, etc. Also our military is the only "global" one. We have 12 super carriers, the rest of the world combined has none.
We don't help enough- Many countries especially those in the UN or NATO believe we dont do everything in our power to help promote peace. We have this seemingly endless military power and wealth (as percieved by other countries) and yet we dont do anything. There have been around 750-800 UN resolutions passed. On just about all of them, all the countries turn to the USA to either fund or execute the mission, or the US vetos it and we are percieved as arrogant or selfish
We help too much- Those same countries that blame us for not helping enough also enjoy accusing us of helping too much and meddling in other countries affairs even when that country has no relationship to the affairs we are "meddling in". Case in point: France about us and Israel and Palestine, or France and us and Iraq.
We create unfair trade- This one is not as popular as the countries that "hate" us also participate in this scheme. But some like to blame Global South poverty on us
We support Israel- Muslims hate Jews.
I hope that gives you a bit of info.