Green Card holders are required to obey all U.S. laws and file taxes annually, just like citizens. However, they face limitations, such as not being allowed to vote in federal elections or hold certain government jobs. Extended absences from the U.S. may also jeopardize their LPR status.
I will not argue further over few limitations for some few countries, that's pointless.
My question, which is more important, remains: "But what's your point? Because some countries discriminate its residents then it's OK?"