One can opt in to the common redistributables (which usually makes sense if the thing you're looking for is covered) or decide to package custom steps into InstallScript files https://partner.steamgames.com/doc/sdk/installscripts. In either approach, Steam will automatically manage the runtime dependency installation for the user before the "Play" button appears.
Thanks for the info. Looks like they're using /silent right there in the example
"Steam customers love a quick and silent install. Add silent or quiet parameters to all run process commands and only add what you absolutely need for the game."
