"The advantage is lower weight compared to pure copper, leading to more dBs per watt. "

Depends on the application, the advantage might be negligible. The mass will certainly matter more at higher frequencies, so these big massive cones on speakers in sound reinforcement bass bins might not benefit quite so much as say a woofer in a decent quality two way home speaker.

I also have heard of copper clad aluminum wire for other purposes and usually it is to save money. One instance it is wires strung from telephone poles. Alot of that is copper clad steel for the tensile strength, again because of cost but not just the cost of the copper, they can put up longer spans and have to set less poles.

I can't think of much reason for aluminum clad copper.