I'm pretty certain that the majority of the people and businesses will abide by such rules, but as always, there is a minority that simply doesn't care. The fact that the majority follows the rules is already a major win for any country. If the non-followers of the regulations such as unregulated exchanges grow out too large, they become a target eventually. No way they can keep running for ever.
Look at what's happening with Binance. It's slowly but surely turning into a compliant exchange. I'm pretty confident that within two years they will have a huge list of countries they do not provide services to, simply because their aggressive we-are-everywhere marketing doesn't work anymore due to their size and increasing regulatory pressure.
Binance made a killing when they started, and they knew exactly that it wouldn't last for ever. People however are shocked.