A600KiloBear is correct when he writes that the income tax authorities will turn your life into gehinom if you evade taxes. Of course, the same could be said of the IRS.
While taxes are higher here in the US, they have been lowered in recent years.
But the main thing is that if you do take self-employment in any way, you must set yourself up as an “osek murshe”, which provides you with a framework for paying taxes and national insurance.
Yes, it is a terrible pain in the well, everything, but you pretty much have to do the same in the US as well, if you wish to obey the law of the land.