I'm widowed after a 25 year marriage.
I had a good married life, but doing it again, as a middle aged, solvent woman, has no appeal at all. Being bereaved is hard and I still have moments where my heart breaks (mostly for my young adult DC), but generally I am very happy with my single life and freedom. I have no desire whatsoever to ever live with a man again, or to be tied to anyone on a permanent basis.
However, I do like male company and sex and miss it, but sex isn't something I have ever been able to treat completely casually. Good luck to people who do, but I'd be a terrible FWB, for example, it's more important to me than that.
I don't want to be someone who picks people up and drops them, but I don't know what the answer is, other than a life of celibacy?