I find the size of Pokémon Home and Scale World inconsistent for Rayquaza. Why is Onix, who is slightly taller than him in the dex, just giant, while Rayquaza is not? Even Gyarados, who is slightly smaller than him in the dex, is much bigger, even though he's like a snake.
I think the size of the ORAS Pokedex is much more representative of reality.

In my opinion, this is one of the few Pokémon in the Scale World range that failed to convey dimensions properly.
I'd recommend Plamo or Select Rayquaza for 1/20 scale.