We have camped for over 25 years and gone through all of this, although with 3 kids there's an extra body in the car so room for less stuff. It does get easier the older they are. Once our tent is up, ours have to empty the car and place items where they go, do the sleeping bags etc.
We camp a lot, 5-6 weeks a year so one solution is to go for longer, then the faff is diluted between more days. 
I agree that less is more. Really really really think if you need it. One good quality chair per person is better than a cheap one and a sofa etc. Cut out the middle man, e.g, if you pack a suitcase, then build a cupboard, then put the clothes in the cupboard and store the suitcase, there's extra steps. We have really tried to make the travelling items into the storage items to cut that out. So kitchen stuff travels in a plastic box, on site I set up a kitchen stand and then the box goes underneath and I upend the plates. Job done, and still keeps a resemblance of organisation in the tent. We have bags for coats/hats, swim stuff, shoes, everything stays and is put back in these unless in use.
If you can, try to keep dedicated camping stuff altogether, so rather than having to remember and pack a tin opener, tea towels etc from you kitchen, have a basic kitchen ready to go.
I have a list on the computer, so print this off about a week before, add any bits for the particular trip and start to gather. When we get back I try to add in things we need for the next trip (more matches etc), or write a list where I know I will see it for the next trip.
I do washing on camp (if there's a machine) as we go along, you take less clothes that way and I try to do a wash either the day before or on pack up day. So much nicer to get home and place clean clothes away, and only having say towels etc to then do.
Get a supermarket delivery or click and collect. No need to pack food.
I would try a van but (and this is the downer for us), if you move the van you have to pack a lot away for that. I don't think you have as much space in a van either, so it really is horses for courses.
Having said all this, we now do have a trailer tent!
I wouldn't say it was much quicker than our last set up of roof box, it's about 90 minutes to fully pitch or strike (an hour if we do quick set up for a stopover). But, it means a lot stays in it, and we just take 'soft' stuff- bedding, clothes, books, swim stuff etc, so I think it saves 1-2 hours each side at home not having to bring items in and store.