The MultiversX blockchain has very small fees (now it is approximately $0.0035)
The network is using less than 0.01% of the energy Bitcoin uses. I believe it's carbon neutral.
I'm not sure about the economics of micropayments, but it's not obvious to me if that's low enough. A percentage without a static fee would obviously work, but that of course implies that the cost of handling a single micropayment should be essentially zero.