Claire, I have struggled with your same emotions! it isn’t too late. Here is the flavor of chores in our house, I don’t know if it will be helpful or not.
In the last year, I have realized my 9 year old can do most of her chores very well, but she is slow. She is still processing the whole event- ie she can’t focus on sweeping crumbs and do mental math at the same time (or really even carry on a conversation). If I stay out of her way and let her do it, it really does get done well. At first, it takes 3-4 times as long as I think it should. Fortunately she has sped up, but they aren’t mundane tasks for her yet, she still is quite engaged.
My next child (7) seems to prefer quickness, but she does slip shod work often if I am not nearby. She has not fully developed the habit of attention. So she gets the “work” but I need to help her develop more attention to detail…..which is tricky when I can just re-do the chore quickly. Currently I have just chosen one chore that she has to do daily and I continue to work on habit training with her on this chore. She has her other daily chores which she might slip up, but we really focus on the one chore, consistently everyday.
For my other two children, (5 and 2 next month), I work right next to them and allow them to do different amounts depending on their ability and attention. Some days my 5 year old does the whole chore, the next day, he barely completes any of it, but stays for the entire time. I don’t think this is willful disobedience, but he is learning through observation on those days, not by doing it.