Comment by snailmailman

Steam has pretty good built in parental controls imo. You can allow-list or block-list games, and block viewing various content on the store, or even entirely disable the store. There are tiers to filtering such as “frequent violence” “any nudity” “frequent nudity” and “adult only”. You can also separately disable the viewing of user-generated content, which I think disables the steam workshop. And even set playtime limits.

Steam’s parental controls are pretty good if used properly.