I don’t know if we ever got good science on whether masking prevents you from spreading it, or you from catching it. If it really only accomplishes the former, then you masking is useless.
If your house is full of vulnerable people who cannot vaccinate, your answer is there. But maybe you should never stop masking because you could bring home flu or the common cold. Which infections have led to fatal pneumonia in vulnerable humans throughout the centuries and will continue to do so until the far future.