Having benefits versus deficits is definitely a good way to go, but again, that is free ad space that is being given up which someone has to pay for, and patreon never will.Not sure how to implement something like that to be honest. Patreon doesn't care as long as they get money. People on F95, for example, can potentially fill that role, and they partially do (just look at the reviews), but I don't think it's enough. It would be nice if this forum could be a point of clarification to save time and money.
How to make this better is a tough question, because I don't think it really solves the global problem I mentioned: this whole industry is underpaid. By making it clearer when a full-time developer misses all deadlines or changes the roadmap, you're not bringing more money into the industry, you're doing the opposite for the sake of quality. It's basically min-maxing something that doesn't even work.
But it can save a lot of money and even potentially slap lazy devs. The problem is to even identify who is a full-time dev and who isn't, who changed the roadmap and who didn't even have one to begin with. We are still talking about indie devs, and most of them work alone, even if they are full-time. The best-case scenario here is for a dev and the community to talk to each other to set the expectations.
After thinking about it, I believe it would make much more sense for now to do the opposite: if a developer delivers updates, doesn't miss deadlines, shows results - he gets some kind of advertising benefit.
One option that might at least add transparency is if a dev has to select milestones and dates at the start of the project, and if that milestone is missed by a certain amount, than there is a unremovable notification that is posted in the patreon indicating it. So it doesn't monetarily hurt the dev, and if there is a good reason for it, than it can give a chance for them to explain it and then it will be up to the patreon to consider it's validity. For those devs that had a project going for a veeeeeery long time, those notifications will be littered within the path and patreons can see all the promises and expectations that were broken along the way which would influence their decision to subscribe so a dev can't just sweep it under the rug.
At the end of the day, I truly understand game development is hard and filled with unexpected issues. I'm not a game dev myself, but I personally know one that have been involved with big projects in real companies and the amount of stress and pressure in enormous. But, when a project is approaching 10 years and the dev is spending more time deleting past comments he made himself and banning users that point this out than seemingly working on the game, we have a big problem of ethics, and I feel there is starting to become a catalog of devs that fall into this category.