I was ghosted in a similar fashion and my ex chooses the absolute worst partners... like you are saying I'm not even spiteful about it they are just objectively really bad people. It's not even that I'm that great, but comparatively she has chose to date really bad guys and it made me feel like shit for so long. Jealousy wouldn't be the right word, it's like the guys she dates make me think somehow I'm a worse option than they are and it's a really awful feeling. I see the way her life has gone and it makes me crazy that she chooses the chaos and instability. I guess the moral is people make bad decisions and if they don't see your value that is their problem, not yours. I am still trying to learn that lesson.