Forward Smash is slow and predictable, Downsmash dosen't kill very well unless you're at the edge, Back Air is impossible to land on anyone with any skill, and Up Smash is...Up Smash.
Well If you think like that then you might as well not play Pit
nah Just kidding. But with pit being able to rack up damage quickly his down side is having a finisher.
Try this. On light characters, such as T-link, Kirby, and G/W, at high% try to do SH Dair or catch them in an U smash and it will send them up and will most likely kill them. A sweet spotted Bair can kill at ridiculously low% I have killed a Samus with this at around 80%.
F smash isn't slow its a beast, just straight up use this.
F tilt not as fast as the F smash but has more range and can be unpredictable at times, a definite kill move.
-Felis
P.S. this is just something that I do sometimes, during a match I don't use my dash attack at all and wait for them to get to higher percentages then I use it on them. If the dash attack isnt depreciated (when you use a move over and over it gets weaker) it actually becomes a potential kill move.