Ike's Uair is active for 17 frames to Corrin's 6 frames. Different uses. Ike's is used to catch air dodges and landings while Corrin's more of a "hit" move. Of course Ike's Nair and Fair are slower than Corrin's. He's swinging a heavy hand-and-half while Corrin's swinging a light, but long sword. Also, you can be as strong of a human or beorc as you want, but Corrin's part-Dragon. That overrides anything just like how Cloud being a SOLDIER - not a SOLDIER, but biologically like a SOLDIER - means screw you to Ike and Shulk. That being said, Ike's Nair also setups into other moves, overall does more, but insignificantly more damage, and can act as a trick because it shares the same startup as Fair. Also, it lasts 4 more frames, 16, to Corrin's 12. Both their fairs are active for 4 frames, but Ike's is meant for horizontal killing while Corrin's is meant for vertical setups. Note: you absolutely do not want his Fair to be any faster. If it was the same as Corrin's at frame 7, it would arguably be one of the best Fairs in the game. Moving on, their Bairs are not the same. I've no idea how you can conclude that. Corrin's moves her forward, is weaker doing 11% clean at frame 13 and 9% late at frame 14 to 16, and the base knockback is 10 higher at 40, but that doesn't matter when overall, Corrin's doing 3% to 5% less than Ike's always 14% from frames 7-9. Also, Corrin can't auto-cancel hers from a hop unlike Ike. Corrin's Bair is more of a utility move to Ike's raw kill and bait move.
For Smashes and Specials... You really cannot compare anything, but their Counter and Corrin's Counter Surge just outright wins because of vertical hit angle to pretty much everyone not named Corrin, Greninja, and Lucario's? horizontal Counter hits. That being said, Counter Surge wouldn't be as great when horizontally-orientated Counters are used as edgeguards. They'd be the same or horizontal ones are slightly better because they're closer to the side blast zones and can gimp instead of launching up and potentially saving instead of killing. Corrin's Up Smash is Greninja, Lucina, Marth, and Sheik's Up Smash. None of them can setup without platforms or customs. The need for precision really limits its use and as an anti-air, the lack of I-frames like on Sheik's and low active frames compared to Ike and Roy's makes it less useful and more riskier since Corrin could just opt for Utilt. Speaking of Utilt, Ike's is used for land traps and ledge options too and it kills fairly well. So... Also, outside of Up Smash, Ike's Smashes are pretty much trash in a 1v1 setting. Side Smash's power and anti-air potential is overlapped by Up Smash and Down Smash's coverage is overlapped by Up Smash. Y'know, I just noticed those overlaps... Really, developers? Really? Yeah, let's make one move do everything the other 2 moves are supposed to be doing... Getting Diddy Uair flashbacks here... Anyway, you could get rid of his Side and Down Smash and Ike would only be slightly annoyed he's missing moves in 1v1, but pissed in FFA and +2v+2 where chaos can help him land those moves.
Also, considering that Ike is a launch character while Corrin is among the final DLC characters... Of course Corrin has more potential? It's only been a month. If everything or about 70% of a character can be figured out in a month, then that character was very poorly designed. As DLC, then that would be a complete ripoff.