Bonuses without any wagering requirements are for me the most transparent and honest one. I don't judge a casino for having a wagering requirement. It is their business and they choose however they want to run it but as an individual gambler, wagering requirements is an absolute turnoff for me.
Fair or unfair, wagering requirements for bonuses exist almost on all online casinos. You have wagering requirements on your deposits even if you don't claim a welcome bonus. Usually it's 1x of the deposit. Some betting sites allow a 0.5x playthrough before you are allowed to withdraw but I have also seen wagering requirements of 2-3x on sports betting, for example.