I think I can kind of understand those users: I like paying for apps but a number of them will still try to abuse me by adding all kinds of monthly payments etc

I think I can kind of understand those users: I like paying for apps but a number of them will still try to abuse me by adding all kinds of monthly payments etc, start adding ads, remove the features I bought it for etc. I also acknowledge there is a problem where authors should be able to secure an income to do security updates etc and I've no "one-size-fits-all solution" to it but I think between - feature keys for new features - optional extra services (support, server side ocr etc) - reasonable fees for special cases (for example I loved to pay USD 1 a year for a user friendly, secure messaging service that promised not to spam me, datamine my data or leak it voluntarily.) - etc there should be room for better alternatives than many of the ones we have today.