You know, my ex told me he was doing me a favor too, by leaving while I was still young and attractive enough to find someone else. Made me mad as hell at the time. (I was 53 btw).
Still, in retrospect, I believe he was right. I did deserve better, and all the men I dated after my divorce treated me better than he had. I did eventually find love again. It would definitely have been harder to start this process at sixty. And I now suspect that there were more infidelities and flirtations than I knew, and I definitely didn't deserve to be treated that way.
If he's telling you that he's not good enough for you, he might just be right.
