To give a baseline: I pay for email hosting through a reputable non-Google company. It costs me about $40 a year, for both the domain name and the email hosting, and it didn't require me to have any technical knowledge to set up. Compare that with, for example, my cell phone plan (around $100 a year) and it seems pretty affordable, or at least comparable to other common bills.
I think it's helpful to think of this in terms of other utility services. People tend to agree that heat, electricity, phone, etc. should be accessible to the non-rich. But those still cost money to operate, and the cost is paid by consumers. (There can be a broader discussion around who should pay for this, but the money does come from somewhere.)
If we decided that electricity could be free, but that it would be funded through personal data collection, that you could permanently lose access at any time, and that you wouldn't be able to get outages fixed in a timely manner, that most people would prefer the current model.
The bottom line is that email is pretty important to modern life, similar to a phone. One way to ensure that your email is reliable is to pay for it.