Steam doesn't require DRM, some games purchased on steam can be run without steam running.
Valve provides a very simple (and easy to bypass) DRM which many games on steam use, this is likely what you're referring to.
Other games use third party DRM such as Denuvo which is hard to bypass and generally hated (can cause performance issues). These games have warnings on the store page.
Ultimately Steam had (has?) a monopoly on the PC distribution market and didn't really take advantage of it to do anything anti-consumer (instead this period introduced a number of prosumer changes like refunds) so while it is a company it's one I trust more than most.
Valve provides a very simple (and easy to bypass) DRM which many games on steam use, this is likely what you're referring to.
Other games use third party DRM such as Denuvo which is hard to bypass and generally hated (can cause performance issues). These games have warnings on the store page.
Ultimately Steam had (has?) a monopoly on the PC distribution market and didn't really take advantage of it to do anything anti-consumer (instead this period introduced a number of prosumer changes like refunds) so while it is a company it's one I trust more than most.