The vast, vast, vast majority of open source software was created by engineers at for-profit companies where, through their line of work, they faced a problem, and after solving it had the insight "hey, other companies may have this problem". On the flip side, the vast majority of maintainers are engineers at for-profit companies who face new problems related to the software every day, and share their solutions back so we can all benefit from everyone else's work.

Its not the old fable of the greybeard in his basement tirelessly maintaining some internet-critical piece of software (though, those definitely exist). Its: "Hey, your business uses Kubernetes and derives millions in revenue either directly or indirectly from it? Mind helping keep it going?"

This is critical to understand because: Vault and Terraform could absolutely have been sustained and grown by the community of its users. There is zero doubt in my mind of this. List the top 50 websites by traffic volume, and every single one of those companies uses both of these products, extensively; many of the companies have engineers devoting effort toward projects like Linux, Kubernetes, Javascript, or Postgres. Vault and Terraform aren't even close to a situation of "but who maintains it"; Hashicorp just refused to let anyone have power in the project that wasn't on their payroll. Far more open source projects die due to this than a lack of interest in maintenance.

The root problem isn't profit motive; its venture capital. To some degree, it is also: projects created to solve the problems of their users before their creators actually have the same problem.