> I call these kinds of behaviours "traditions", but I'm not sure if there's a better term for it.

In psychology that kind of thing is referred to as "superstition".

More specifically, "superstition" in this sense refers to the phenomenon of copying someone else's successful approach to a problem you have. (In your example, getting views on youtube.) Since you don't know what parts of their approach matter, you copy the effective parts and the ineffective parts equally.