Sorry about all the text dumps, y'all. I just can't help but feel that either I'm not seeing how Ike's strengths can hold him up in this meta, or others aren't seeing how many great tools the rest of the cast have gotten in able hands.
I think you’re highly underrating Ike in this game. I say that, not with contempt or disdain, but that it takes time to adapt. I’ve played Ike in Smash 4 and Project M, and to me he feels like a completely different character in this game. Instead of thinking “Ike was buffed.” Consider, “Ike was reworked.”
Weaknesses:
The reason I disagree with saying Ike simply plays different is that he's too much of a one trick pony like that, and it's not even a good enough trick. Let us not forget that Ike needed a lot of work to elevate him from his placement in Smash 4. He still has his old Smash 4 issues of his aerials being slower and starting above him, Bair is no longer as large, his aerial cooldowns are awful and really hamper his edgeguarding, and his air acceleration is low, making him far from an "aerial king". He can't even do a move as basic as runoff Fair anymore without sending himself to the limits of how far Aether can recover.
His ground game being the same compounds the problem, because rather than helping him cover the holes in his air game, its existing weaknesses are only exacerbated in this game. I've already been watching players like Ryuga and Ryo playing to compare the differences between my play and higher levels, and it seems to me like him getting manhandled on the ground is a common theme. His run speed and initial dash are both terrible. He's more easily spaced out by longer, safer attacks that are faster than Ftilt and too long to stick Jab or Dtilt out. He already couldn't deal with enemy projectiles too well before and now they're safer than before. He's more vulnerable to shield pressure, especially crossups, since his OoS options are slower in Nair's case, less safe in Fair's case, harder to land in Bair's case, and shield drop and shield grab are both nerfed. He himself can't pressure shields since his moves don't do much damage, other characters have quicker options and Ike has nothing like shield damage, command grabs, or kill throws to dissuade opponents from holding shield.
Other Characters:
I know Ike can do stuff like aerials out of shield and dash cancels and whatnot... but so can most everyone else. It's not that Ike does not have tools at all, but they're inferior tools. How do Ike's tools compare against Simon having longer, safer pokes, quick get-off-me options, crossup options, deadly projectiles, and an extra landing option in one package? Against Wolf having a transcendent projectile to force opponents to approach, but once they get close he has a long fast Ftilt, safe Fsmash, and fast aerials to fight with? Against
Ganondorf, of all characters, having superior aerial frame data, powerful long tilts, crossup options, greater reward off of grabs, a command grab mixup on top of a fast horizontal hitbox move, and
faster, stronger, bigger, less laggy versions of our Fsmash and Usmash (what the fug), without losing any of his existing power or reach? Adding insult to injury is that Bowser, whose Fair we amusingly observed nearly mirrored our own prized autocancel Fair back in 4, now has more power and less lag than ours on top of maintaining its autocancel abilities that we lost. If he can't pressure as safely, can't space as safely, can't edgeguard as safely, can't land as safely, can't secure kills as safely as other characters on the roster... then what's his specialty supposed to be? It isn't power. It isn't speed. It isn't safety. It isn't finesse.
I don't feel it's prudent to adopt a "This is fine." mindset in regards to his abilities. In Smash 4, opinions of Ike only fell as time went on and his weaknesses became apparent, and if those same weaknesses are still here, then that doesn't bode well. I don't know the rest of the roster well enough to say anyone's overpowered, but I strongly feel Ike is definitely underpowered compared to them.