"The results I found were shocking: there were two clearly sustainable open source projects, but the majority (more than 80%) of projects that we usually consider sustainable are actually receiving income below industry standards or even below the poverty threshold."
I fear that open source is actually just the tech industry's group of underfunded-but-vital-infrastructures that are constantly either forced to work for poverty pay or go corporate/private(and externalize the costs to society as a whole). Similar to single-payer healthcare systems, domestic violence sheltering, child protection, pet shelters, and education systems.
Specifically that I fear once these entities try demand to be paid what they're worth, there will be criticism and controversy.