But to get visa to go to the united states is very complicated. I have brazilian passaport and i can't travel to united states, but i can travel to whole europe without visa.

I would like to visit united states, but because of visa process, i don't have motivation to do it

Obtaining a visa can indeed be a complex and time-consuming process. It's unfortunate that it's discouraging you from visiting the United States. Hopefully, in the future, the visa application process becomes more efficient and traveler-friendly to encourage more people to experience all that the US has to offer.