ok, well , shall help this matchup thread by saying that i have fought a really good ganon before(zeonstar, hes ridiculous with ganon) and ill say this match up 60-40 kirby, because while kirby does have great grab combos and such on him kirby will really alot on bair and if a ganon plays smart punish/dair spam style your ground game, included your fsmash will be gone so you have to really on air,
because ganons b moves have great priority that wreck kirby completely on ground, but now, so next because you will rely on aerials which while kirby should be able to rack damage on ganon quickly with, kirby won't kill ganon for a while if not gimped/ kirbycided,
but ganons will kill kirby at 100% easily and if they are smart with, timing, spacing, and punishing they will often see air approaches(or ground) very easily and thunderstomp them, which ganon will easily kill kirby with, or upair them(shorthopped and started kinda early of course)
so ganon can't do much to kirby while in air but the thing is as kirby, you have two options, go full pressure and try to barrage them with air assualts till you can sheild poke them or be really defensive and try to punish(which i prefer because that somewhat limits ganons punish style) and you can also spam up-b which is annoying to ganons
but the mains time like i said should be trouble in this match is killing because ganons can kill you at early 60s and most time youll be dead by 100 while you won't kill good ganons untils like ridiculous percents with gooddi and use of fastfalled upairs or timed fairs unless you get early wop, and ganon will just often at that point knowing that info try to counter you making it hard to kill him while if he gets a few good hits your done
so in a short version: kirby can really rack up damage on ganon and he can't do much until you want to kill him which then ganon will be a pain in the butt and most times you will die going for kill if not really smart, so matchup is 60-40 imo in kirbies advantage