What you do is you become a "VC" and get a bunch of guys to build on top of "open source" with a X-as-a-Service based subscription model, and then you contribute pennies back (and usually: just posting issues to the open source stuff you use to get slaves to slave away for free).
And btw. it's not super easy for companies to contribute on a voluntary basis - their investors or stakeholders would not allow/like it. What they can do is declaring it as "donations" and paying it from the marketing budget.
People need to treat open source as contributing openly to society with no expectation of return. Conversely there is no guarantee the maintainer has to listen or do anything anyone says.
If people want to support you can charge to support.