What is the purpose of Float Stone?

Question

I'm currently playing Pokémon Scarlet. I decided to stop speedrunning near the end due to all the fun being sucked out, not to mention the lack of time for my Pokémon to properly leveling up leading to much stress. So I started to come up with a plan to cross-breed to come up with the perfect Zorua.
However, when I was searching through my items, I discovered that I had several Float Stones. The description matched this;
"An item to be held by a Pokémon. This very light stone reduces the weight of a Pokémon when held." And I was extremely confused. Afterall, what does less weight even do? And don't some moves also have more power due to more weight?
Thanks for listening to my annoying-ness uwu

Answer 1

Float Stone reduces the weight of the Pokémon when held. The moves which are affected by weight can have their power either reduced or increased with a drop in the opponents' weight.

Grass Knot and Low Kick have their power reduced with a decrease in weight. Heat Crash and Heavy Slam can potentially get a base power increase when the opponents' weight is reduced. With these moves, the lighter the target is than the user, the greater the power.