The wheeled uprights might not fit in "all" aircraft even if they are within the size limits listed by the airline. Some aircraft have unusually shaped overhead or underseat spaces (especially underseat spaces for window seats) that may not be able to hold a wheeled upright that is close to the airline's size limit.
I prefer squishy bags like backpacks or duffel type bags or similar for carryon use. If necessary, they can go under the seat relatively easily, avoiding the need to gate check them.