Yep, this is exactly the case. There is a BRC-20 token called "SATS" that just recently minted out, meaning there is no more of them to be claimed. And after that happened we witnessed a sharp dropoff in transaction fees:



Whats ridiculous is the vast, vast majority of BRC-20 transaction have been mints. People just mint the token into existence and then sit on it, never transferring it anywhere. The real winner here is the inscription services that people pay to mint the tokens on their behalf (otherwise you need your own full node to do inscriptions).