I believe this, the identification and the articulation of additional value, is the problem with FOSS sustainability, and it's urgent that we resolve that.
I hope I am onto something with the idea of crowdfunding specific commitments, as I have sketched there: https://archives.gentoo.org/gentoo-project/message/3735cd917...
The mental model behind this is quite simple, and I hope that once adopted, it will avoid a lot of unproductive behaviours and expectations on both sides, of the producers and the consumers.
It's strange that there's so little crowdfunding happening to deliver free and open source software. One of the very few prominent examples is https://www.kickstarter.com/projects/andrewgodwin/schema-mig...
Basically I believe in offerings which promise specific qualities (timeliness of responses and bugfixes, roadmap features schedule etc) and cover the costs of development (including market rate salary for the developers according to their skills which they use to develop and manage the project).
I am currently developing this with the aim to roll out my first experimental offerings. I am keen to help others to adopt this approach, so everybody is most welcome to reach out to me with any questions.