Wario in smash is a representation of WarioWare Wario, and they made him have many weak hitting moves (Aside from Waft and Shoulder Bash). To really represent him as a WW rep, they made him move surprisingly fast, but personally, I believe he should be strong for his smash appearance.I'd say Wario's strength is inconsistent and that he seems to be portrayed as a lot less strong nowadays than he was in his "glory days." From the early days to the middle of his history, he's just downright nutty though. Even comparing him to Mario, he can easily walk away from things that mean an instant death for Mario, or on occasion even Bowser. He flings around a MASSIVE dinosaur like it's an action figure, can throw the Shake King hard enough for his helmet spikes to pierce the walls of his ship, etc. Even his other forms show how ridiculously durable he is. His body disintegrates in his Zombie form and occasionally his fire form, only for Wario to reform instantly. Vampires are well known for dying very quickly to sunlight, whereas Wario just turns back into his normal self upon exposure. And of course, in Wario Lands 2 and 3, he was just downright unkillable (except for Rudy's hand thing). Not to mention he has killed several demons and deities with his bare fists, whereas in other Nintendo games demons usually require some sort of magical or holy item to kill.
In Mario Spinoffs and Smash Bros, he's portrayed as one of the stronger characters, but less strong than Bowser and sometimes DK. I feel like arguments can be made for DK's strength, but I'm pretty sure both Wario and DK have greater feats of strength than Bowser. Also Wario is pretty weak in Smash Bros., where most of his attacks hit like a feather duster and from what I remember, got his butt kicked throughout Subspace Emissary. He also has some really bad instances of weakness where he can struggle to open the door of a port-o-potty in WarioWare.
To sum it up, Wario has ridiculous highs, and some extremely low lows. Comparing a "composite Wario" to the composite forms of all other Nintendo characters, I think there would only be a few that could actually best Wario. As of right now though, he isn't that strong.
Wario in smash is a representation of WarioWare Wario, and they made him have many weak hitting moves (Aside from Waft and Shoulder Bash). To really represent him as a WW rep, they made him move surprisingly fast, but personally, I believe he should be strong for his smash appearance.
We all have already seen RelaxAlax's video, thank you.
And can we please stop claiming that Wario is represented in Smash by WW, just because "Speed". Capitain Falcon is fast, just as F-Zero cars are, but no-one claims, that his moves like Knee of Justise (Forward-Air), represent F-Zero, just because CF is fast, and calls it a day. Same with Wario's moves like Up-Air (Clap) or Back-Air. Wario never used those in any form, yet everyone seems to claim, those are taken from WW, just because how fast he attacks. They are not from WarioWare: They are Smash originals. And these are the once, we have to get rid of, instead of replacing moves, that actually reference something. *Points at Smash For and Project M*
Also, Wario doesn't looks that fast in Smash. Maybe he was in Brawl, but he feels slower in latter games. (Or this is just me, idk)
Don't get me wrong: Wario in Ultimate is best Smash Wario by far in my opinion, but he still can be improved, to represent Wario Land and how strong he is (Without painting on clear references, like Side-Special). For example, Forward-Air. I feel like this is the one, Wario had to copy from Mario. Just imagine: Wario dunks his opponents. Wouldn't that be glorious and strong?