Is anyone else here skeptical of legal marriage?

As a breadwinner, why would you agree to get legally married? Why would you sign a document saying that your partner can choose to take your house and half your money away at the drop of a hat if they want? It seems pretty risky, especially given the high divorce rate in the US and the fact that you have no way of knowing how you or your partner will change. I know there are certain financial and tax benefits, but those seem too small to compensate for the otherwise huge financial risk constantly hanging over your head. Looking at legal marriage as a financial agreement, why do it?