if you are saying that a site that's registered in Curacao is a red flag then you're wrong with that assumption. And, there are many sites that start providing their services to customers and they don't have to be 5 years in the business.
The sites that go bankrupt and steal players money are almost always "regulated" in Curacao or Costa Rica the last 15 years, not Italian regulated or UK regulated, it's always certain countries that people kind of know isn't really regulated well