I'm sure there is a trend here. The first few years I wouldn't pay taxes anyone, unless it was huge amounts that they wanted to legalize. As time has gone on and there are more and more centralized exchanges, more KYC etc, more and more people pay taxes.

If you have low undeclared amounts it is easy not to get caught. For example, let's say a friend sold you $200 in Bitcoin some time ago, which today is $800. It is easy to spend those bitcoins and the IRS will not find out. But if you have 10 undeclared Bitcoins you have a problem, especially if you want to spend them.