The goal is to get some form of value back for sharing it... from those who otherwise wouldn't contribute (as a few do already). Even if seemingly small, it's better than nothing.
I'd recommend you explore what other projects are doing for creative solutions. For instance consider Slint, a UI toolkit, offers their software under a viral copyleft license, a paid-for closed source license, and an "ambassador" license [1] which allows the code to be used in closed source software for free, but with the requirement that the Slint developers can use the derived product and its logo in marketing material for free.
[1] https://slint-ui.com/ambassador-program.html