Enough people pay for Nebula and Kagi and Fastmail to make them profitable, even though YouTube and Google and Gmail are free. You don't need to get everyone in the world who uses the free service to be willing to pay, just enough of them to fund your project.
There's actually an advantage to the paid business model vs ads in that you don't have to appeal to N million people in order to pay the bills: you only have to appeal to `expenses / subscriptionPrice` people. This means you can cater to those people more aggressively and turn them into fans rather than just users, while also saving time on the features they don't need (reducing `expenses`).
(I'm a happy subscriber to all three above-mentioned services and would immediately sign on for a paid Firefox fork like OP suggests.)
There's actually an advantage to the paid business model vs ads in that you don't have to appeal to N million people in order to pay the bills: you only have to appeal to `expenses / subscriptionPrice` people. This means you can cater to those people more aggressively and turn them into fans rather than just users, while also saving time on the features they don't need (reducing `expenses`).
(I'm a happy subscriber to all three above-mentioned services and would immediately sign on for a paid Firefox fork like OP suggests.)