I originally ordered a 5 seater to save a couple of bucks thinking we could go 3 wide in row 2. We even did a car seat fitment test on test drive, but that was with forward facing car seats and latch anchors and not with boosters. We sprung for the 7 seater when the same config as our MY5 order became available in MY7 back when inventories were low and wait times were a best-guess. Figured it was a good safety net for future friends or family use or heaven forbid our van went out of action for a bit (it is a Chrysler...).
In short, with our household we ended up needing the 7 and I got lucky. The second row was frustrating when I tried to go 3 wide with 2 boosters and I would've been more than upset if I didn't have the 3rd row available to me. Legroom is huge, which is what our focus was when shopping. But the narrow center seat and buried seatbelts are a PITA for smaller kids. LATCH anchors are there on the outboard 2nd row seats, but even they are more difficult to use than other vehicles I've been in and out of.
In short, the car isn't perfect and I'm super happy I ended up in a MY7 for my use case. I've also found along the way that the vehicle has a TON of utility and I wouldn't want to reduce that in any way (like by removing the center seat functionality perfectly.
Unintended benefit of MY7: Being able to slide 2nd row forward with seat backs left up to secure bigger loads securely in the hatch. I do this sometimes when moving stuff around for work.
Food for thought. My mother in law has a Toyota Venza 1st gen and she had to take the kids for us last week. I was blown away when we fit the forward facing and BOTH booster seats in her 2nd row without any issue at all. And the kids could do their seatbelts. Damn lol. (The rear seat tether was in a dumb spot though, in the hatch trunk floor rather than on the seat back. Also... it's a Venza LOL. No car is perfect. )
When we put 2 boosters in middle row the kids are completely independent, other than sometimes not being able to reach the seatbelt and I have to get it for them so they can buckle in.
When we do 1 booster in 2nd row with forward facing and 2nd booster in back the 2 older kids are independent, other than the same seatbelt issue and use operating the seat for access and sliding forward for rear foot room.
When we do 1 forward facing in 2nd row and 2 boosters in 3rd row its about the same as above - except they can tend to fight when trying to buckle in at the same time due to the buckle placements and someone trying to get into the others' slot. It is what it is, at least when we have to help for row 3 we pop the hatch and help from there as oppose to inside the car.
Anytime someone is in the 3rd row we fold down the middle center seat. But if someone is in a booster in row 2 they have to buckle in before we fold it down.
Pro move: If 3rd row is up you can prop up the rear sub trunk cover behind the 3rd row seatbacks and have a deeper trunk to stand taller items upright if you need to.