Better to say what hyip site earn as what they can scam as majority of hyip are just scam/ponzi which can't run for long time. But except few bitcoin casino can run for long term because what they earn through house edge is pure profit which they share with their investors.

I think bitcoin casino site can earn big amount constantly for long term than hyips if they can keep their users engaged in their platform and keep hosting several contests, bonuses, giveaway etc.