IIRC, our cruiseline provided an accessible shuttle that took us to a location where we could easily catch a water bus. There are special rates for disabled people
"Finally, passengers with wheelchairs can buy single-fare "disabled tickets" at heavily-discounted rates from ACTV ticket booths and Hellovenezia offices. Each ticket is valid for 75 minutes, and a companion travels free.
Once you have a pass or a supply of tickets, you'll be able to get between the city's various "accessibility zones" on the map by using the water buses. (The city claims that about 70 per cent of the streets in the historic center are accessible by vaporetto.)
This strategy works especially well on the Grand Canal, the Giudecca Canal, and the Lido, where the No. 1 and No. 2 routes are wheelchair-accessible."
Taken from this website https://europeforvisitors.com/venice/articles/accessible_venice.htm
I don't know how accessible the 'people mover' is, I'm afraid.
I'm lucky in that I am able to walk a bit, so I walked over a couple of bridges while OH carried my chair. It would take more thought if this were not possible.