Referral links is good when you have it but if you will use it you will have the 100% of winnings and as far as I know many gamblers used other referral link then they registered and when they are playing they will not win a good amount of money but for those people who have spreading Thier links then they will earn a lot of money.
Referral should not be called as winning, it should be called as earning or maybe reward/commission for your effort to bring players to the casino with your referral link.
There is no guarantee that those who spread their link will earn a lot of money, no matter who are they including popular influencers.
The commission will always be depending on how their referrals gambling activities, the higher the activities (deposits + wager) = the more commission they will get.
I am totally agree with your thoughts. I don't know why people always give important in popular influencers. We can only effort to spread our links to attract gambling lover's. Either popular influencer or non-popular person no one can assume who will be their referrals.