My point isn't that Squirtle and Charizard are better then Ivy, it's that they're better enough at certain things that they aren't redundant. Top Pokemon Trainers tend to favor Ivysaur but they still use Squirtle and Charizard to certain degrees. There are even certain match ups like Fox where Charizard does great.
Fair and Nair are also super good if you space well.
Fair is good in neutral, but it's slow enough that it's hard to cover Ivysaur's landing and Nair is punishable on hit if you land during it. This leaves Ivysaur with a slight weakness to frontal attacks and a huge one to attacks from underneath while landing.
Fair is especially too slow to be used OoS. Nair and Bair are okay but they're still frame 6 (9 when factoring in jump squat), which while not slow aren't amazing OoS. Squirtle's got a frame 4 Nair, frame 5 Fair and Bair and much better air mobility to punish with. Charizard is the real champ here with a frame 6 Up Smash and frame 4 armor on Fly.
Squirtle doesnt have enough mobility right now to be safer than ivy.
Squirtle doesn't have raw movement speed, but has the 8th best aerial acceleration in the game. He's around Pikachu-level when it comes to overall mobility, which is good enough to get the job done with his small body. His frame data is superior to Ivy which makes him better at dealing with zonebreakers who are able to get into Ivysaur's space.
Razor leaf is just one of the best projectiles and the mobility ivy has in the air with it just really good if you know when to use it. It's not meant to camp out everyone by itself, which is why you retreat back air (tho the other moves are good too).
Agreed, Back Air is also just really safe on shield if spaced well.
Grab is actually really fast for a tether one, and it hasnt felt bad to use like yoshi's or zero suit's.
It's still pales in comparison to Squirtle's and Charizard's. It can't be used out of shield, and it's much easier to be interrupted. It's a much bigger commitment.
I wouldn't nerf the whip, i think it's pretty fun to catch people with it, but up-air and down air should be nerfed so that ivy can't do everything by itself, charizard should be better for ko'ing and that's just not the case right now.
Yeah Up Air is probably PT's best kill move right now, but in all fairness it can only really kill opponents above Ivysaur's head. It's harder to kill opponents who have strong disadvantage with. None of Charizard's KO moves are superior to Ivysaur's Up Air, but they're more varied so Charizard can kill in more situations. Up Smash kills out of shield, Bair and Fair kill in neutral or advantage, F-tilt kills nair the ledge, Flare Blitz punishes predictable movement, ect.
If they increased squirtle's mobility then it would be best for fast and safe quick attacks and to combo, whereas right now ivy is the best to combo with.
Blatantly untrue. Squirtle's combos are far superior. His grab is much faster and can be tomahawked and leads into longer, higher damaging strings. On top of that, his Fair can combo into grab. Dash Attack also leads into long combos. And F-tilt. High Level PTs almost always start as Squirtle. Ivysaur's grab is much harder to get without conditioning the opponent first and when you do it still doesn't do as much damage as Squirtles.
And none of your points address the fact that Ivysaur hates being backed into a corner and forced into close quarters situations. Squirtle has amazing frame data (frame 2 Jab, frame 4 nair) for when he needs a fast "get off me" option and Charizard has an great OoS game as I mentioned earlier.
Just watch any high level Pokemon Trainer player. A lot of them don't use Charizard as much depending on the match up (they're slowly starting to use him more though), but they do still use the whole team. If Ivysaur is so godly compared to the other two, while aren't they using the "optimal" strategy of just sticking with them the entire match except when they need to recover?
I'll take Zard buffs and slight Ivysaur nerfs if they come, but I don't think they're necessary for the PT meta to progress. It's been progressing fine as is. I think Squirtle is kind of in that sweetspot though where he's good but not too good, there's not much I really want for him.