Disney does most things really well, but transport is NOT one of them. The buses are not all that frequent, the queues for them (especially at peak times) can be horrendous, and the organisation is appalling.
A lot of the time, you have at least on wheelchair passenger. When this happens, the driver shuts the front door, opens the rear door, lowers the ramp, gets the wheelchair and companions on board and locked down, raises the ramp, shuts the rear door and then opens the front door so remaining passengers can board. All this faffing around usually takes around 10 minutes. The when you do get on board, if the seats are full, people will NOT move down to take up all the space, & you find the average bus leaves half full. I only remember one driver insisting that passengers move down to fill the bus in the 8 days we were there.
At closing time, it seemed that at least half the drivers were at the end of their shift, as nearly every 2nd bus that arrived went out of service although queues were at there longest. We were at Pop Century which has a peak capacity of over 10,000, and since we were there it's twin Art Of Animation has opened. It's a good thing that a lot of the patrons of these don't travel to the theme parks every day or you would never get there.