People who don't have slides say you don't need them. People who have slides say they couldn't live without them. Advantage of slides is obviously more room. Disadvantage is slides add weight and reduces your fuel mileage........a bit.
Of all the "things" on or in an RV that can cause problems, slides are way down below a whole bunch of other stuff.
Personally we started with a diesel pusher with no slides and moved up to one with two slides. We really liked the first one and really like the second one, except it has more room, and slightly less fuel mileage.
