Unless it concerns powers specifically given to the federal government by the US constitution that would be unconstitutional: "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people." (10th Amendment).
If you do not like the laws in your state, vote to change the laws.
If you do not like the laws in other states, discuss and persuade the voters of those states to change their laws.
The constitution is a broad documented to be interpreted
It's not a step by step manual or grocery list
> If you do not like the laws in other states, discuss and persuade the voters of those states to change their laws. Or better yet and occasionally easier get the federal government to change the law for the whole country, benefiting everyone
This is only an option for the most privileged among us. What are the options for someone who is gay and doesn't have the means to move to a less bigoted state?
The right of people to govern themselves is important even if we disagree with how they do it. Note the EU Human Rights Court came to the exact opposite conclusion a year after Obergefell, finding no right to marriage for same sexual couples under the EU convention on human rights.
If you look at constitutional law in western Europe, no country has a court that intrudes as much into social issues as the US Supreme Court.
You're leaving out the massive fights from states that did not want to recognize gay marriage, which could have easily gone the other way. The same process will repeat with marijuana prohibition and the states fighting it may succeed this time. What would have happened if gay marriage stayed as a patchwork of legal statuses? What will happen in the long run when marijuana is legal in many states but continues to send you to prison for decades in others? This is not a stable situation and the exact reason we need the federal government to do things instead of leaving it up to the states.