U can always find other ways to reward authors, for instance you can send a tip.
Or youn can build a better version of it for free. We look forward to that.
To your critism I disagree: Firstly there is lots of effort and cost that went into building this service. Also the fees are not that high and there is no other way to reward an old post via an upvote that does not cost anything to you. TBH your complaint sounds like you are just looking for something to bitch about. I doubt that you care about rewarding authors, since then you would just use our feature.
I have been looking for this feature for years, if its so easy to build why has noone done so.