If you have asked yourself this question before, then in that moment, you have probably lost perspective of what you are doing.
It is easy to conflate effort, with quality. Subsequently, when what you’ve spent a long time making (and refining) isn’t as amazing as you think it should be, you start to get confused.
Take time away from what you do, and it’ll be clear whether what you are doing is any good. The longer the better. And don’t even think about factoring in how much effort went into it. Your audience doesn’t care (that much).