Mr. Game and Watch is underrated, but like mid-high C-tier. I wouldn't say he's better than, say Shulk. Unless we're talking doubles, then he's like A+, SSS tier easy.
First, your argument. Chef IS a good, underrated projectile, especially when B-reversed or wavebounced. His uair, while strong, is pretty unreliable, especially compered to other killer uairs like ROB's or Dedede's. His aerial game is certainly top 5, but Sm4sh does have a lot of ground game, and his aerials are not as good at shield pressure compared to Brawl. especially his bair, but no one ever has the patience to wait out the multi-hits
. Landing a judge is a rare treat due to its startup and cooldown, not to mention that being able to hit the same # twice in a row makes 9 rarer. Fire doesn't combo into any aerials past like 30%, you can get a fair at very low %s, and nothing else. It's gimping ability is off the charts though.
Other weaknesses. He cannot guarantee a kill if his life depended on it. None of his *great* aerials kills before 140% unless you're at the edge with fair, which still doesn't kill early. His smashes DO kill early, unless you don't hit the sweetspot. This makes it very hard to kill turtling enemies, especially since he doesn't have a kill option that beats shield. That's a huge issue with G&W because he is light, so he can't trade blow for blow until the opponent is at a high percent. All the high tier characters you mentioned were "light" still die much later than G&W.
He isn't hopeless though. His down-throw grab game and combos are exceptional. Properly played, he can rack up damage incredibly quickly with combos that do around 18-26%. His aerials are amazing for gimping and stage spiking, which somewhat but don't completely make up for how much effort is required to kill with him. His speed upgrade allows him to follow up from Chef more then he's ever been able to, and his really low ducking profile along with Judge and Bucket make for game-changing X-Factors, depending on the MU.
All in all, he's much better than people give him credit for, but he's not amazing, not by a longshot.
Oh by the way, he isn't that fast on the ground. His run speed is 28th, putting him behind the likes of Mewtwo, Rosalina, DK, and even ROB, all characters known to have middling speeds. But its OK because he's fast enough to punish rolls if he keeps running
(Stupid Dr. Mario, that's part of the reason I dropped him)
