Streaming services parental controls work on the principle of profiles: you set up one profile per family member and assign a PIN and age rating to that profile. It also prevents family members from interfering with other members’ favorites, viewing progress and suggestions.
Open Netflix in a browser and go to your account. From there you can manage Parental Controls:
Disney+ works exactly on the same principle as Netflix:
Amazon Prime Video
Amazon Prime Video has a bizarre setup: you can create individual profiles but only one PIN can bet set. This PIN is required to access content beyond what is permitted or to purchase paid content. This PIN can be enabled for all devices or only specific ones.
Apple TV+ content is available to family members through the sharing the Apple TV+ subscription. Age appropriate content is then allowed according to the profile of the child logged onto the device. Note that Apple TV+ can be accessed on any browser through https://tv.apple.com/ .
If you are using an Apple TV box attached to your TV, you can easily switch users to deliver the appropriate content. Although I suspect most of families won’t bother and will stick with the main user for all uses.