There aren’t two sides to the argument… The ISP’s customer is paying to access that data, adding another fee to the originator of the data is double dipping, plain and simple.
I think it’s telling that generally the only network providers who can charge these fees are the ones with outsized market power - for example the largest ISPs in my country, such as Telstra and Optus don’t do any settlement free peering and charge everyone for transit to get bytes into their network. But the smaller ISP I’m on peers with Netflix and AWS and Microsoft and literally anyone who connects in to internet exchanges around the country, and funnily enough, even without charging content providers extra fees for data I’ve already paid for, my connection has better general performance, I pay a competitive fee compared to the other ISPs, and their network isn’t swamped by all the data…
I think it’s telling that generally the only network providers who can charge these fees are the ones with outsized market power - for example the largest ISPs in my country, such as Telstra and Optus don’t do any settlement free peering and charge everyone for transit to get bytes into their network. But the smaller ISP I’m on peers with Netflix and AWS and Microsoft and literally anyone who connects in to internet exchanges around the country, and funnily enough, even without charging content providers extra fees for data I’ve already paid for, my connection has better general performance, I pay a competitive fee compared to the other ISPs, and their network isn’t swamped by all the data…