Sonic vs Wario is about +1 or so in warios favor. He pretty much has the same advantages over sonic that he has over most characters. Hard-to-hit-ability, weight, and kill power. It used to be much worse because sonic doesnt have a major range advantage over him and we were hard pressed to find a move that beat bite.
But its more even now because sonics fair does actually beat all of warios aerials so you cant just dair us for free anymore. We can punish your landings better than most, and avoid your kill moves because we are fast and mobile. Wario is fat so its easy to string low percent stuff on him, but his air mobility makes it a pain to chase him in the air for follow ups around 50-60 and after. Wario is going to spend most of the match baiting and punishing from the air, and sonic is going to spend most of the match baiting and punishing from the ground. But warios punishes are going to be easier and heavier (knockback wise) while sonic punishes will be harder (both in difficulty and in damage racking.
bite is a good tool against sonic, but only if the sonic is not expecting it. If we see it coming we will just go behind you for a free hard punish.
Sonic is at the height were sometimes if we grab you from the air, your legs dangle and we get an air release punish and sometimes we dont. but sonic can kill you at lower percents (~130) from the GR.
shielded f smashes give sonic a free f smash punish.
Dont let sonic get the lead.
We can charge side b (the one that makes him move backwards slightly and makes a small hop on release) and the beginning hop has invincibility frames for us to beat all your moves and extend the lead.
fart is a problem. the only way sonic wins this is by not dying early and holding a lead. if we get farted on at 70, it screws the whole game over.
the more patient player will win this, but its easier for wario due to his weight.
I found a pretty good match that shows how the sonic wants to play the matchup
https://www.youtube.com/watch?v=nD7zUyh1xdk
first match is just the sonic being a better player, but the send match shows how certain wario aspects like bite and patience want to be utilized.