What I am planning to do with my 5YO and almost 3YO is to bring a stroller to help navigate rope drop crowds and park exits crowds (without being scared that my kids will not be able to hold my hand because they get pushed by someone), then we will park it somewhere strategic (ex.: Fantasyland in MK, entry of TSL in HS, Land pavillon in Epcot Future World...) and have them walk between attractions.
I think it will be useful when they are exhausted at the end of the day or around nap time, as a "crowd control" strategy, as a holder for our stuff (shirts, snacks, water bottles etc) or even for the kids to have a bench to sit on while waiting for fireworks, parades, etc.
When we went last year my non-napping son fell asleep in the stroller while we were leaving the park - we were in shock! But I think Disney is so stimulating that it's nice to have the option!