There are lots of cryptocurrency payment gateways. Each of them have different processing fees and transaction fees. some of them charge 1% to 5% fees on each transaction. which is a huge amount but merchants have to pay this amount. But there are payment gateways who charge the lowest amount like, one payment gateway only charges 0.23% processing fees on transaction. I find it very attractive because merchants will get more from it and it will be more beneficial for them eventually.
The thing is very simple and logical, if you think you're ok with the ones with lesser fees on transactions then choose them, but on a real sense, we are likely to have it this way that if you weigh and compare the low trans charges gateways from the high ones, literally you will discover that those that have lesser charges tend to have more traffic than the ones with high fees, also it is better to always run a transaction with lower charges but frequent and consistent than running a high charges with no patronage for the service, which means, little profits can accumulate to something big if we choose to consider others than our own interests first.