They do just that laws and criminal cases require evidence time and verdicts then appeal processes and further such things. Does there exist criminals that never saw prison yes, does there exist criminals who got out fast or got easy jail time yes. But that’s on individual judges and juries.
Heck why do most white on black crimes want to prosecute their cases in middle America because the jury is more likely to agree with the white person committing the crime same as police.
No justice is perfect but the notion that they don’t face anything is wrong. And there is continuously more and more evidence being gathered against the people responsible for Jan 6th, the fbi is just removing the foot soldiers so that there won’t be another January 6th incident. Because it’s not the rich and wealthy that went and broke into the capitol it’s their foot soldiers and domestic terrorists.