Because your friend is a casino player, he will probably end up losing everything he's won. That is how it works, casino's know this and they are fine paying out big casino wins for the most part.
They will never get any of my money because they realised I will only win long term, so they will make up an excuse not to pay me.
I know that slot or casino games will always be profitable for the house in the long run, but that's not what we're discussing here, we're talking about withdrawal. I really question why my friend gets paid while you don't (despite him being a slot player and you being a sportsbook player).
I have had no issue withdrawing from 99% of sites
Previously you also said that you don't experience problems with withdrawals on 99% of the sites you try, why not stay & become a loyal player on 99% of those sites?
Usually someone tries a new site because there are programs such as promotions that are profitable for users, and these programs are vulnerable to cheating, don't you feel like you're taking promotions and using them less wisely?