I think I would rather try to live in an open marriage situation (as long as I also got to not be strictly faithful) than in a monogamous but sexless marriage.
I’m pretty much in that situation now. No sex with my partner in over 15 years. Plenty of physical affection, we get along really well, he cooks for me, I enjoy our time together. But sex together is pretty much off the table for us, by mutual inclination.
I even recently considered having an affair, but since we don’t have an explicitly open relationship that would be a betrayal of trust that the relationship would not survive. So I carry on.
Roddy