Exactly, and open source companies make great money too. ElasticSearch being a prime example, yes AWS eats a large share of their pie, but who cares, the pie is absolutely huge.
Another example is GitHub and Gitlab. Both got big by leveraging the open source community for marketing. Imagine all the resources GitHub spends to enable open source, that's a cost center that will never go away. If they hadn't done it though, they simply would never have become big.
And then Gitlab one ups them, sacrificing an even larger share of the pie, allowing free private repos and free on site deployments. And still they're carving up a big chunk of pie for themselves.
In my opinion it's the only way the future is going to make any sense. It's not a race to the bottom, it's a race to more balance between the rewards of beating the network effect.
If you want to build a new company in a space that another company is already offering significant value, then you are going to have to offer even more value. And if there's no more value go squeeze out of your functionality, and you're already not charging your users, that means you're going to have to give part of your company to the users. It's a mathematical inevitability.