It looks like taxes increase and any kind of post-life planning can be done with a few legal filings rather than getting married. Is there any real benefit? It kinda seems like it’s just a way to trap people in relationships, probably traditionally, the woman.
Just to be clear on the first two points, you can designate anyone as your health care proxy. Check your state for specific applicable forms. In general if no one is designated though it will default to a spouse.
Health care proxy is also different than power of attorney, which sometimes people get confused on.