Not necessarily — plenty software still ships with the third party supply chain bits incorporated as binaries, including commercial software. User is relying on security of one or more in a chain of upstream vendors.
See Cyberpunk 2077 DLLs for instance.
https://twitter.com/CDPRED_Support/status/135660404767189811...
Cyberpunk “builds” their game with a software build system, but not all of it is them building it.