My knowledge comes from having worked in the online gambling industry and knowing a lot of people who live in or have lived in Malta.
As a Swiss, I don't know whether I should be offended or relieved that our usual suspect, Zug, does not seem to be involved in this.
This has also led to a proliferation of local talent which looks passable in a suit, can open mailboxes, is versed in law and/or accounting, and does not steal excessive amounts of money.
The business model is basically "stuff that is not provably illegal yet". During the Cold War, Switzerland got away with a lot, but in recent years, many formerly lucrative areas of business started drying up thanks to stricter money laundering laws etc. So for an ecosystem that has evolved to accommodate financial engineering right at the edge of legality, cryptocurrency seemed almost a custom made niche.
This claim is false. The internet is littered with corpses of Malta-based gambling sites that exit scammed their playerbase. This doesn't occur in jurisdictions where the gambling regulations are "decent".
Edit: unless you mean "decent" from the perspective of unscrupulous gambling sites who are looking to scam people out of money.