What if your tennis doubles partner said: "I don't think you are a very good tennis player. I'd rather play doubles with another player." Would you still feel confident being that player's doubles partner? Because in tennis, as in sex, part of good performance is feeling free to go for it. Playing without fear. Difficult to do where your partner has told you outright that she doesn't think you are very good at it.
Butforthegrace,
Is your tennis doubles partner thee best tennis player in the world who can judge who is and who is not a "good" player?
Is your WW thee greatest lover in the world who is the standard bearer for what is considered great sex?
Maybe your tennis doubles partner is not very good at tennis and selfishly blames you for how bad the game has gone?
Your tennis doubles partner, your wife/sexual partner - are you always going to defer your value to what someone else's opinion of it is?
Or, do you look inwardly and be honest with yourself as to how much you honestly contribute to the game or in the bedroom?
Can you be aware of yourself in knowing how much you are hindering or helping in the game or offering pleasure, demanding pleasure, or sharing pleasure in the bedroom?
Or, do you have any say about yourself outside of what sports partners and women you happened to be married to tell you?
If your sex partner tells you that you are not good sexually then it is up to you, and not anyone else, to take that feedback and one - think of the source, two - determine the truth to it, and three - what you are going to do about it.
In the end, it's one's own responsibility to be aware of themselves, be honest with themselves, and make the effort to be the best at what they want to be.
Some people, like a WW, will always tell you that you may not be so great sexually (no matter how great you may actually be) because they need to in order to suit their narrative that they use to commit their infidelity.
These are the last people on earth that I would base any sense of my own self-worth on.