You’re both right.

You need repetition if you’re not creative.
Creative ideas don’t look like ads. They’re more likely to get noticed and they’re more likely to cut through.

Rational ads tend to get ignore or filtered out. So the repetition helps them eventually cut through. Think of a boring ad you’ve seen that eventually watch and realise you’ve seen it 100 times before you’ve paid it any attention.

Then you go back to ignoring it.

Creativity helps with cut through. And changing the idea maximises the ability to take root and take share of brain space.

All in my opinion.

I have no formal quals in this area