Explanation
The point of an avatar is continuity. A generated person who looks different in every clip reads as stock footage, and an account that appears to feature a rotating cast of strangers does not accumulate the familiarity that makes people follow it. Fixing the avatar across a run is what turns a batch of clips into something that looks like a channel.
Avatars are most useful in exactly the situations where casting is the bottleneck: covering many products or many concerns, running the same message for different audiences, or maintaining a cadence a real presenter could not sustain. They are least useful where the specific person is the product, such as a coach or an agent building a personal brand, unless the avatar is consistently theirs.
Because an avatar is a photoreal depiction of a person who does not exist, it is squarely inside what platforms now detect and label. Treat disclosure as automatic rather than optional.
The common mistake
Changing avatars between posts because a new one looked better. Consistency is most of the value, and swapping resets it.