So far I have not encountered merchants with independent payment gateways since I usually see CoinPayments. In my opinion, payment gateways are necessary to act as a secure and trusted middle-man for transactions especially for websites that aren't that well known.
I agree. Payment gateways, especially trusted ones easily help gain a customer's trust which increases the sales potential for smaller websites.
What's awesome about Paybear is that their fee stays the same whether you send $1 or $1000. The more money you spend, the cheaper they are if we compare it with Paypal, stripe, etc.