True. However, i highly doubt most people here actually pay taxes. Same can be said for most types of people offering any kind of service over the internet, particularly if they are not making a living off it. And in my country if you're just doing some gigs to get by it's pretty much cultural not to declare anything. Even when it comes to offline jobs. If you need someone to fix your door, most people you will find are certainly not paying their taxes. It is what it is. How risky it is, varies from country to country. Most people won't get caught unless they're making a solid salary out of it and making it pretty obvious. It's still risky though.
It's a matter of personal choice: Risking legal issues VS Having money to survive. It often comes down to it given that, at least in my country, taxes are brutally high, and people make jackshit. As an example, renting an house costs about the same as the average salary. If you're a freelancer and you're making, lets say, 1500 euros, over 40% of your salary will go to some form of taxes. If you make something stupid like 700 euros, you still have to pay social security. So most people in this situation really will avoid taxes, otherwise they don't eat. In Spain, for example, you have over 10% unemployment rate, and a few years ago you had something like 25%. But that obviously doesn't represent the amount of people without a job. People just work illegally. It's cultural.
But then again, there can be consequences. Is it moral? Is it immoral? It is whatever you want it to be. You're disrespecting laws creating by other people, not by god. Some of those people incredibly corrupt. My former PM has millions of dollars and nobody knows exactly why. Didn't go to jail. Anyway, you can still get fined if they find out, so just live with it. I wouldn't recommend anyone to test it, unless we're talking about really small figures.