I was about to ask you the opposite, Reflex.
Jab, D-Tilt, F-Tilt, N-Air, F-Air, and B-Air can all be crouch-canceled until middling percents and there isn't much of a beneficial dynamic between F-Air and B-Air (in Brawl, B-Air was fast and safe with little reward, while F-Air was noticeably more powerful and riskier). Forward-B isn't good for anything but edgeguarding and VERY specific space control, because virtually any move will clank with it, leaving the opponent in neutral position before Ivysaur has any chance of capitalizing on it. Her grab is incredibly low to the ground as well as slow, and virtually all of her grounded space control options hit low, so opponents' N-Airplane or something similar can get in with little trouble.
She has no way to safely get in on any good projectile, so she's forced to clank with/avoid them and camp with Neutral-B, which is only viable on certain stages (you need space and platforms). Down-B has very exploitable cooldown relatively easy to clank out with most characters' aerials (either a N-Air, a F-Air, or a D-Air) or any ground move, preventing it from being very useful outside of ending combos and the occasional getting back to the stage from getting straight up.
Her best KO options depend on a 50/50 throw mix-up that depends on an unreliable grab. Her best combo option, N-Air, hits people away upon landing mid-move and is SDI-able down into a crouch-cancel with little trouble. Her out-of-shield game is weak (N-Air and U-Smash aren't so great against tight shield pressure) and she's not good at dealing a lot of damage at once without relying on bad DI or opponents shielding Forward-B (which they should never have to do).
She's obnoxiously good at edgeguarding, as shuffled F-Air hits any and all sweetspots, and her other attacks work really well for disrupting people offstage. She just really, really struggles getting people offstage in the first place.