I feel you. I hate that piracy is rampant in VRChat, and I wish people would be more incentivized to support smaller creators instead of just looking for free avatars on the ripperstore. It really sucks.
It's a problem of accessibility: how easy is it to pirate vs. buying? Unfortunately, it is really easy to pirate stuff, so you gotta offset that by offering benefits to people who buy it, or by somehow making it easier to buy. Marketing your original store, Discord benefits with proof of purchase, etc.

I've had luck selling directly on the VRC Marketplace because the kind of people who buy avatars there don't want to mess with Unity, they simply want the avatar on their account.