We’ve just moved from one bad policy to a different bad policy. This is standard politics: Some people think something is bad and want it banned; others think it’s good and want it not only legalized, but condoned. The possibility of the government just not being involved is barely considered, if at all.
The role of government should be to protect the lives, freedom & property of the people in its territory from being wrongly taken by force or fraud. This means the only behavior that should be banned is people harming other people.
We do not need government to license, register, perform, or define marriage. Government has a role in forcing parents to care for their children (neglect being harmful), and in arbitrating break-ups if the people breaking up choose to involve the government. Those roles can be performed without it having anything to do with marriage.
Christians should oppose government involvement in marriage for many reasons – one being that government is therefore also involved in divorce. This leads to Christians violating Paul’s instruction in 1Cor 6 to settle our disputes in the church, not in the secular courts. And in the previous chapter, we are told that the immoral behavior of those outside the church is none of our business.
Having said all that … today’s ruling doesn’t really change much. The USA is still heading the way it was heading before.