Former IEEE member here. I don't understand the distinction you are making. IEEE is also a closed-access publisher, and furthermore is essentially a monopoly if you are an EE researcher (unlike CS where there are well-regarded open-access conferences and journals).
In short: if you're an EE researcher, paying for IEEE isn't a choice; if not, there's no reason to join.
In short: if you're an EE researcher, paying for IEEE isn't a choice; if not, there's no reason to join.