I would also like to point out another alternative with which Mike Perham, author of Sidekick, has been immensely successful. He makes significant income by selling commercial licenses that also have certain premium features [1]. Isn't it possible to make it simple to sell commercial licenses? It'd be less favourable approach in terms of the open source spirit, but I think it can benefit everyone in the long term. Authors can be motivated to maintain the project and provide business value at the same time.

Some commercial features can include things like dashboards, monitoring, or notifications. Of course, it'd likely work if the many businesses would find the project useful and would be willing to pay.

[1]: https://www.indiehackers.com/businesses/sidekiq