In a nutshell
Ganondorf is a typical heavyweight, possesing slow and powerful moves and having sluggish movement. Ganondorf is a character riddled with weaknesses, from range problems to an unsafe moveset to a horrible recovery, so using him means knowing exactly where his limits are and utitlising his limited tools as effectively as possible. Ganondorf is largely infamous for his Down Aerial chains and his Flame Choke followups, which are vital for players looking to win with Ganondorf
Ganondorf holds the distinction of being the last character on the tier list, at the H level and at 38th place. He is one of the slowest characters in the game, making him very easy to punish, and the removal of L-canceling makes Ganondorf's aerial approach considerably worse; his lack of a projectile and his sluggishness also limits his ground approach. The addition of a slow, predictable recovery and a bad defensive game brings Ganondorf down even further, allowing many characters to easily outmanouevre him. All of this give Ganondorf the worst matchups in the game; Ganondorf holds the distinction of being the only character in all of the Smash series to have absolutely no advantageous or even matchups.