I remember when I was little my mom would cook for a few hours on Sunday to pre-prep meals for the beginning of the week and pre-cook/freeze meals for later in the week. That is a huge time saver so you can spend time with them right away when you get home because all you have to do is pop prepared stuff into the oven (or scoop out of a crock pot)
It's time for your 9 year old to have some chores (or MORE chores if he already has some.) He can clear the table and load the dishwasher while you spend a few minutes of well planned out activity time with your little ones... And you can spend some one-on-one time with him when the younger ones go to bed (even just 20 minutes of your time is valuable).
As exhausted as you are, try doing chores once the kids are in bed. (When they get in the bathtub, throw their clothes right into the washing machine... then when you get home the NEXT evening, start the washer right away... then you can fold clothes after they go to bed because the cycles should be done by then)
Also, spend a few hours on the weekends to do chores and errands and plan activities for the family to spend time together for the rest of the weekend so you have quality time.
I know life is crazy now, but I promise it will evolve as they get older and can do more for themselves. Think about how your 9 year old can take a bath by himself