Im not really familiar with NFT but iirc didnt you need to allow the contract or whatsoever on your wallet before you can use them if you are a first time user. On top of that, there is transaction fee as well aside from the opensea fee wasnt it? so taking 5% cut is actually proper. Well yeah it might seems alot but Rollbit is not really exclusively NFT marketplace but its a gambling site that has NFT marketplace in it as well so they get less volume compared to opensea thus they charge higher fees
The importance is the token will still have a big bull run of cryptocurrency market in 2024 and 2025. Its total and circulating supply will become less and less with time because of Rollbit team's Buy back and Burn program.
Well actually I tend to notice most people will dump their RLB when bull start. Just like a week ago