Cryptocurrency payment getaways have the lowest transaction fees so that the business owners gets more profit from it. accepting cryptocurrency as a method of payment opens you to more customers internationally. it will helped your business to increase profitability and revenue growth.
I doubt if Bitcoin payment gateways truly have tye lowest transaction fee except when using lightening.
One of the major challenges with using Bitcoin as means of payment is the high transaction fee involved and these transaction fee most times if not all the time is actually paid by the buyer and let's just be realistic that as a buyer after purchasing goods at a said price, I wouldn't think it wise to make payments with my Bitcoin because of the transaction fees but I would rather trade my coin and make payments in my local currency, hence I'm saving cost .
I personally don't think using Bitcoin as a payment option will increase your profitability but rather I think it basically broadens your payment option for people who want to make anonymous transactions.
Right in terms of low transaction fees and speed I can only see that it would advantageous to use it if the Lightning network is used.
Besides that Bitcoin as a payment option might attract some tech-savvy customers, but this implies that it also comes down to what the product line is that the business is offering. I guess if you run a flower shop it is less likely as of now to attract people who prefer to pay with Bitcoin than it is when you run a business that in general is more appealing to tech-savvy customers. Or even when it comes to luxury goods, it is not uncommon that Bitcoiners are inclined to use their crypto to pay for it, but it is difficult as you can quickly be tapping into a grey zone and in some countries it is even forbidden I think to sell luxury goods of > a certain value for cash or cash equivalents. If I am not mistaken I think I read about something like that.