that is the old way to get bitcoin quickly, when they get a lot of bitcoin they usually disappear and the site cannot be accessed, for those who have struggled in the crypto world for a long time, it is clearly fraud, but for beginners they might be tempted with fantastic profits.
I used to experience something like that, tempted by Ponzi investments with fast profits, but I already know what Ponzi is now, apparently a scamer who continues to deceive beginners by luring big profits within 24 hours.