"Getting Jeff'd" is only an existential crisis if your goal is to own the majority of the pie. Postgres's contributors come from a bunch of different companies who all manage to make enough money off of Postgres to pay them [0]. That is the only financial metric that really matters for funding a FOSS project.
The problem with these companies is that they actually were trying to make large returns for shareholders rather than simply earn enough to keep paying the developers.
They wont get totally cut out though - Jeff Bezos will send the bugs they find while servicing their $10mil a year service contract to the raggy startup of five to fix over a weekend between their 3 jobs while sustaining themselves on the most expensive food they can afford - a bowl of discount ramen.
