with ganon's neutral, it's less about him lacking quick options (you have nair and uair at frame 10 and 11, respectively; dash attack is surprisingly good; you have solid spacing options with your aerials and you can also do silly float shenanigans to suss people out somewhat) and more about commitments you have to make. his least committal options are probably ac nair and full jump float.
if you ac nair and don't hit a shield, you can still just be outright dash dance baited into stuff. it's not terrible, but ganon isn't that quick so it's hard to use it to pressure someone with their full options available. this wouldn't be so bad, in and of itself, except his other neutral options still don't let you get much outside of harder reads.
full jump float is nice, but if you get called on it, you can't back out of it quickly (14 frames of float commitment,iirc, before an aerial can start). cancelling it by pressing down still has a commitment period (also 14 frames, iirc). you can dj out of it at any point, but if you get hit by someone going after your float, when you dj'd...
otherwise, you get things that are tricksy, but not that solid. sh-bair-wl in or out (or uair-wl), dash attack, dacus. spacing fair can be safe, but if it's shielded you still can't always reliably followup on it, and that can also be dd baited by the quicker characters. basically, most of ganon's options are high commitment, and you can space them to be rather safe, but his safe spacing puts you in a situation where you're not necessarily able to capitalize on the opponent, if they decide to retreat and reset.
that also wouldn't be so bad, because they're going to give up stage control, but the whole commitment thing means that you don't have a good way to just stop someone from guessing your option and going over/under you as you do it.
if his punish game was actually unique to him (i.e. fox wasn't able to bait out someone and punish into high damage combo into reset into usmash/shine gimp; etc....) this would work out well, because when ganon does touch you, you tend to take about 40% in 3 hits and you're now probably also in a bad spot, stage control wise. but, in this meta, good punish games aren't the important aspect of a character. getting to use your punish game is what matters more, so ganon having a hypothetical 10/10 punish doesn't matter if his neutral sits at around 4 or 5 and you have better characters with a 7 or 8 punish game that have 7 or 8 neutrals to back them up.
i'm also not trying to sweep away ganon's strengths. he does A LOT of damage very quickly (especially damage per attack), he has really good non-disjointed range, and is a beastly edgeguarder, especially now that he has float. but those aren't severely important traits to have in this meta. basically, if you can outplay your opponents, ganon looks like a god, because you always take the right option and they take 50% in 3 hits and probably die. it doesn't always work out that way, though, and ganon lacks tools to make the opponent take actions that he can capitalize on easily.
i guess the tl;dr is: ganon's strengths are there and they're very potent, but they aren't unique to him and the best parts about ganon aren't important to meta success; and his weaknesses are what's important to meta success.
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