Well, that question has already been answered. It most closely resembles Brawl, particularly in that efforts were made to drive the game away from competitive potential. This is exemplified in brawl by the clunky movements, tripping and unbalanced as shit characters. These factors were fixed in Sm4sh and sma5h, but in lieu of them we have ledge-stealing, no dash dancing, insane recoveries on every character (Yes, little mac can actually recover, I main him and the only time i have problems offstage are when i cause them myself. His side B just happens to be better than his Up B for recovery so nobody seems to be able to figure that out?) and the "Final D Only" mentality applied to For Glory mode, the "Competitive" aspect of the game, alongside a piss poor decision of -two stocks- per game, one game per set.
Also, in 64 and melee, the controls are anything but simple at high level play. Being able to adequately perform advanced techniques and combo in those games takes an immense level of dexterity and patience, and that's just to perform them. Learning and mastering them is another beast in itself. It takes literally years to perfect.