If you do that, the normal education is redundant. You wouldn't put a university student in class to learn multiplication; it's an insulting waste of their time. Why would you do the same to a 10 year old who mastered it years ago?

Not really—public school takes up 6+ hours of every day, and I'd like my kids to have self-directed time as well. If we tried to do some sort of after-school tutoring with mom that would deprive them of valuable time to choose their own stuff to work on.

And what would be the point? If we're right that their mom is better equipped to teach them than a teacher is (because of time to dedicate to them and a personal relationship and understanding) then what do we gain by having a teacher do it too?

(This isn't the thread for the socializing argument, because OP started with teacher qualifications. I'll just add that we are aware of that concern and have strong mitigations in place.)

Not really. There are only so many hours in the day. The time between school and bedtime is extremely limited and involves other time consuming activities such as after school sports and eating dinner.

I work on homework with my kid every day and after all those things it's not like we have time (or she has energy) to fill in holes in her at-school learning