To approach this on a bit more narrow of an interpretation of the question since the fair use aspect has been tackled really well already; the Youtube creator backend [Studio] offers a broad ‘toolset’ that creators tackle copyright and other issues with.

But - it’s not perfect and certainly falls behind in a few areas so there are 3rd party software integrations that really expand how a creator can better manage their channel.

Salesforce is a really comprehensive (and expensive af) option; if you’ve ever added an extension [add-in] to excel - Salesforce has their own vendor marketplace for apps that you can install directly into your instance - if none of them tackle the problem directly you can also just build an app within the platform that does exactly what you need.

It’s kind of like a sandbox where you use a CustomObject as the clay to mold it into being whatever is needed.

For the clips the channel uses in their videos I imagine there is something of a backend repository they maintain with all the relevant information associated with each of those clip_ID that are searchable in the event of a copyright claim hitting their video.

But there is also Microsoft Dynamics, Google Workspace, AWS, etc., which all essentially exist to address the same thing.