They likely will until Gabe either sells his shares or someone else inherits them and sells them. (Though maybe whoever inherits his shares might continue the legacy, who knows). At that point Valve will probably either get acquired or go public, and become another shitty tech company, beholden to quarterly growth above all else.

Valve is a great example of a private company not becoming another cog in the machine, but that probably won’t last forever

https://www.pcgamer.com/microsoft-would-buy-valve-if-opportunity-arises-said-phil-spencer-in-leaked-email/