Maybe I'm naive, but I always assumed the majority of Bitcoin users doesn't do it to evade taxes. There's one very simple reason: if your small Bitcoin investment turns into a small fortune, you want to be able to tell a honest story so you can legally use your money to buy things.
Well it's a combination. Because if it turns into a small fortune, it becomes a "warning sign" for the governments. It tells them that "this guy has become rich suddenly, let's get some of his money".
My governments' greed keeps growing. A few years ago, the "wealth tax" was 1.2% per year. Now it's 2.12%, next year they're planning to increase it to 2.84%. That's a tax on unrealized gains, and I'm pretty sure that's by far the highest wealth tax on the planet.
It's not the highest, but it's very high. I think Spain has a very high wealth tax but I don't live there, so...