basically you played really well the first stock and then started spamming side b way too much. you limit your use of shield and just predict and punish peach's movements.
Peach is definitely a more horizontal than vertical matchup, a lot more matchups are horizontal for us than I initially thought
Fox is horizontal the thing is most matchups, we're dominant either horizontally or vertically
the hardest thing is figuring out which it is on some of them so that you know what to try and abuse more
i think the problem people have with Peach and Fox is that one of the basic skills in Smash is to aim not for where the opponent is, but where you think they will be
and those two characters turn that on its head
like for example
a lot of your strings fail because you are used to gravity being a factor, when peach can make it a non factor
jab to dsmash at low percents is **** usually
but peach can float out of hitstun and hit you for it, when pretty much no other character can do that
so it adds one more element to the horizontal chase game: they can now airdodge, jump, attack, or stay put
so you just have to account for that extra option when playing peach, and knowing that it's one of her best options, you can assume they'll use it more often, which is why fair is ****
always keep that mixup game in mind
like i forget which game it was, probably the first one, where you blaze out of the gate and punish dark pch trying to float out of a juggle with 2 fairs, i would have waited on the third, cause he's going to change what he does after being punished twice