By 11, he needs to take more responsibility at home (as you are saying) and at school (teachers expect more).
So, what are his consequences for not being ready? And what is your technique? If you're nagging and reminding (natural), stop. It's not working. He's still counting on your physically dragging him to the door and putting his shoes on him, as if he were 5. Maybe he needs a written list vs. verbal reminders - and that's fine. But he can make it himself. He can get an alarm clock or an alarm watch, and use it.
Leave him behind. He's 11 and can stay alone for an hour or so, at least during the day. If you are heading out for errands or ice cream, he misses out. If you are going out for school supplies, he goes to school without what's on the list, and he doesn't get to tell the teacher that it's your fault. If he forgets his lunch, he can eat what's in his snack bag - he will not die. Or he can spend his own money to buy lunch wherever he is, and do extra chores at home or for neighbors to replenish his own wallet (walk dogs, water flowers when neighbors are away, and so on). If he's not ready for school and he misses the bus, oh well. He can miss the day (and sit in his room, not in front of the TV) or he can get a ride from you when you are good and ready, and he can go in the office for tardy check-in to explain to the principal why he didn't think it was important to get to school. (This worked in 1 try with my son.) If you have him in a summer program that you paid for, and if he doesn't get to it in time, then there's no paid-for program in the fall (or whatever his "currency" is). If you're late for work because of his tardiness, then you tell him your pay was docked and you can't afford XYZ that he wants. If you ran out of time for the dishes or making dinner, then put him in the kitchen and have him call you when dishes are done and dinner is ready. (The first time my son balked at walking the dog while I cooked dinner, he demanded we switch. I said, "Great!" I walked the dog while he tried to figure out how to make simple pasta and sauce with broccoli on the side. I got a lot of respect after that one.)
This is a good start for the school year, too - you will want to stop reminding him to do his homework or remember to take his project to school. Let him get a few points knocked off his grade (it's only middle school!) or have to stay for extra help or detention. Let him have to deal with the teacher himself, without you intervening at all. It works! And actually, it's a life skill that he needs to develop - it's far more than a punishment, and it helps immensely for parents to see it that way. Just like when they learn to walk, we have to let them fall and not hold their hands all the time. When they learn to ride a bike, the time comes to take off the training wheels and let them wobble a bit.
Sit him down, tell him the plan and the consequences. When the situation arises, follow through - do NOT give in to the whining or anything else!