It was a really awkward situation.
Shitty service providers are at the core.
For a very long while they were pedalling perfectly illegal "solutions" that were simple and cheap and clients ate them up like cookies. There was hardly any incentive for the Service Providers to strive to be legal, because legal solutions are less cost effective than passable illegal ones. Meanwhile, the Banks just gobbled up whatever because they felt︀ it was not their business to be their client's taxman. So shitty solutions from shitty︁ providers was what got the deals done.
Fast forward to the moment where banks and︂ bankers have a criminal liability in assisting clients with tax evasion and then the cleaning︃ initiatives of the EU - all of a sudden, these banks found themselves with dozens︄ if not hundreds of structures that could no longer hold water on their books. Of︅ course all the clients were informed that there was a problem, but we couldn't exactly︆ go ahead and spoon-feed the clients the solutions, so as not to be seen as︇ co-conspirators in Tax evasion.
Most of their Service Providers turned out to be absolutely inept︈ at playing the rules of the game, some even tried to hold up the narrative︉ of the evil bank, we'll find another. Long story short, by D Day only about︊ 20% of those whom we warned changed and adapted to a more compliant structure (often︋ by virtue of a small formality), the rest had to go and so they did.︌ I guess EPIs and Crypto soaked up a large number of these folks, the rest︍ became compliant when they realized no real bank would take them anymore.
Another issue is︎ that once you're kicked out of a failing/blacklisted Bank or EMI (ABLV anyone? It was️ destroyed by the US in 2 weeks), other banks and EMIs are (should) be EXTREMELY careful about onboarding you - a few too many bad apples roam to a new bank and its the next in line for retaliations...
Long story short, have your s**t 100% ready before you come to the bank, don't try to work it out later or as it goes along. And bother thinking past the "offshore = no tax" mentality, because things are incredibly more nuanced and being able to navigate intricacies is now the name of the game.