This always gets brought up when Steam and DRM are mentioned in the same sentence, and it is true technically speaking. However, I'm not convinced it matters in practice.

In reality, the vast majority of games on Steam will not start if Steam isn't running. And some which appear to work at first will have strange errors later on. There's also no way for me as a consumer to tell if a given game has DRM before I buy it. That pcgaming wiki has been wrong for me before (many times), and sometimes games that used to work will no longer do so after an update.