I think Falco matchup isn't too bad. He must kill Ganon somehow, and Falco hasn't the best approach and has lots of trouble landing killing moves. SDI the chain spike and it'll never kill, powershield the lasers (they really annoying, but I think it's still far from impossible to deal with) and Wizard Kick out of Illusion (which can hit him while try I mean, nowhere near 0/100, more like 30/70 or 25/75 Falco. It can't be as hard as IC. Well, that's just my opinion.
Vs Falco is however unwinnable.
I do agree that he's not as bad as people make him out to be. I mean, Falco can actually get owned if he slips up, and he doesn't kill that easily in general.
As for me, the chainspike is the least of your worries. Just let him laser camp you or hit you with a N-air (stand on a platform) and no more chainspike.
Bait the **** out of him then and find a way to combo him, then find a way to hit him with a sparta kick to get him offstage so he'll be gimped. Or F-smash him. Either works.
Personally me, I also think DDD really isn't that bad of a matchup for Ganon. I'd actually push that one to be 65/35 DDD. Yeeeeah he has a chaingrab and his B-air is gay, but that is all he can do. He can't actually approach worth crap, and his Waddle Dee camping should not bother you at all if you are patient (like any Ganon should be). He'll then try to F-tilt you, which you can also try to powershield, and then you can F-air his head a lot whenever he whiffs. Fullhop N-air also works really well on him, especially if there is a platform nearby (you might get U-tilted at KO percents though). Sure, he'll still **** you a lot since Ganon just sucks, but Ganon doesn't have to roll over and die instantly without a fight. He's much less tedious to approach than Yoshi too.