[babyface00]

Well, your question
I don't see what marriage has to do with the Gov't and/or the Constitution.
can be interpreted in (at least) two ways:

Why is government involved in marriage in the first place?

Why does it matter how marriage is defined from the standpoint of the government and/or Constitution?

I was addressing the second, mostly because now that the benefits are in place making marriage a legal definition and a key to benefits, the historical reasons for the first are rendered largely moot. In other words, even marriage were relegated to religious institutions, or left up to the individual, the fact that federal, state, local and government-regulated private benefits all exist based on that status means that (one of the) the core objection(s) remains.

[rhombus]

Why does it matter how marriage is defined from the standpoint of the government and/or Constitution? I was addressing the second, mostly because now that the benefits are in place making marriage a legal definition and a key to benefits, the historical reasons for the first are rendered largely moot. In other words, even marriage were relegated to religious institutions, or left up to the individual, the fact that federal, state, local and government-regulated private benefits all exist based on that status means that (one of the) the core objection(s) remains.

Understood. I do agree that marriage is now dead. How can one now legally restrict marriage to only two people? How can one prevent marriage within families to take advantage of inheritence laws and avoid taxes? I know, just get a judge somewhere to agree. Ah welcome to the era of trial lawyers.