Customer Advocacy - who owns it?

Hello,

While doing some research into advocacy (stories, case studies, reviews) it's not clear who's typically responsible for it.

Advocacy seems to fall between any these departments:
- Customer Success
- Marketing
- Product
- Sales enablement
- Customer Advocacy - separately to any of the above

Would be interested to know who owns it in your experience, and who should own it ideally?

Thanks

Simon