>>29443550No move with a miss chance is inherently better than a move without, especially when it has no secondary effect.
Your argument rests on baseless assumptions that it won't have any of the numerous ways to make Waterfall good, including just a really high attack stat.
Feraligatr isn't even the fucking best waterfall user. Mega Gyarados and Azumarill are much stronger competitively. Just further proof that you're talking out of your ass.