Any studies on user case studies as reinforcing copy?

Content provider for a website heavily pushes case studies as a way of helping the user to make their financial decisions.

For example: Jane is a 32 year old single mum who works part time, she choose to do X, Bob is a 24 married man with a child who is working full time, he choose to do Y

These case studies end up being 4 paragraphs with bullet points and can sometimes number 20+

I have an opinion of how useful these case studies are but I'm wanting to know if there's any studies that have been done, I tried googling but searching for UX case studies doesn't yield anything relevant unsurprisingly.