Ugh. Anyone who's saying the only point is for moves like Grass Knot and Low Kick are missing the point of why they were added, considering that weight-related move effects were not introduced until Gen IV.
The Pokemon games take place within a fictional world. It's Gamefreaks goal to immerse their players into the world. Because of sprite limitations... erm, let me show you:
If were were to judge a pokemon's size visually, Caterpie's sprite takes up approximately half the amount of space as a Snorlax... so Caterpie is half the size of a Snorlax? Or what if we were to judge a pokemon's size based on what we've seen in real life... so then a Caterpie is smaller than our pinkie. Snorlax is the size of a grizzly bear? A great panda? A teddy bear?
If not for the anime, I think a majority of us would have disagree with what size pokemon are. Even the anime would get it wrong (cough, more frequently) if not for the games explaining to the animator's what size pokemon
We should be glad that Gamefreak took the time to include this information in-game. Sure, it's not perfect and may seem like "random numbers" some times, but I think we're taking this information for granted.
they're incredibly ridiculous aswell if you've seen jwittz video on youtube on pokemon height/weight.
it's important but sometimes it looks like they just pick a random number without thinking about it.
it's important for moves like grassknot and there is a few others as sonic pointed out
I've seen Jwittz's video about this. He spends half the video whining that in-game Charizard isn't the same size as anime Charizard, as if it was the game was wrong. -_- His entire video just says how either the anime or his personal opinions disagree with the games, as if the games were wrong. The only arguments where he compares how unrealistic a pokemon is to its real-life counterparts, such as Wailord, he then (rightfully) refutes his own arguments.