I think I see his point though, and it's not quite the same as working on FOSS. He made a sibling comment about helping a "multi-billion dollar" corporation (CloudFlare) for so little reward. So in his view, this volunteer effort didn't really help regular people that much, and instead benefited a huge company mostly.

People usually work on FOSS because they have a personal interest in a project, and want to share that with everyone. So we end up with stuff like device drivers for hardware where the mfgr couldn't be bothered to make a Linux driver, or various useful utilities, a whole OS (which everyone can use), etc. What we don't see much in FOSS is "enterprise software": stuff that's only really useful if you're a huge company. Where's the FOSS alternatives to proprietary human resource management systems, supply chain management systems, etc.? Generally, stuff like that doesn't exist, because no one wants to spend their free time working on things that they personally have no use for, and no one's found a good business case to make a company producing an open-source version.