Deciding When a Draft is "Final"

One difficulty I have with writing and publishing is figuring out when I'm done, when after multiple drafts I've reached the "final" draft.

I typically work on something until I feel it's as good as I can make it (at least at the moment) and then start submitting. If it gets accepted, I must have been right that it was ready (I've had a couple of pieces get accepted on the very first try, which is an amazing feeling). If it gets rejected (which happens almost all the time), I want to reconsider whether it's "finished."

If I get nothing but form rejections, I have to consider carefully that the piece may not be as good as I thought. But if I get positive rejections, with comments about how my piece made the shortlist or was seriously considered or whatever, then I know that the piece is good, but I have to consider two possibilities: 1) the piece is ready and I haven't found the right journal, or 2) the piece is very close to being ready and I still need to revise more.

Looking back over something one more time is usually a good idea, but it's still really tough to figure out when it's done. I've had pieces I was sure were as good as I could get them only to revisit them a year later and see a bunch of changes I can make. Or I have other pieces that have been rejected over and over, but I look back over them only to still believe that they are good and ready to submit.

Eventually, if a piece is never accepted, I stop sending it out. Except, I have trouble retiring something if part of me still believes in it. Sometimes I'll go years without looking at it but then decide to go back to it one more time (my most recent publication was a situation like this where it had been rejected dozens of times over a period of close to a decade and then after yet one more revision, it got accepted).

So I'm curious if anyone else has thoughts on how do you know when you're done? When do you decide something is ready to send out? Or when do you decide to give up on something if it keeps getting rejected?