I believe convenience and actually wanting to give something back to the creators would have many people pay for pro features, since it’s actually “Pay once, use for life”, which is a rare and welcome sight in this subscription-flooded world. And it still leaves people with low income the option to (legally?) circumvent payment. Not sure how sustainable this is as a business model, but I think it’s pretty nice compared to being forced into continuous payment.
Is it only the hassle of self hosting that stops potential customers from having the paid features for free?