There have always been ads in the PS5 interface if you're connected to the internet and logged into your account. I fully expect they'll add more ads in time.

For now all of the ads go away if you log out of your PSN account. You can even leave your PS5 disconnected from the internet entirely although I've had games refuse to launch while offline because they insisted they needed an update that hadn't been downloaded yet.

My biggest complaint with the system is still the controllers which are designed to break after a year or two and cost $80 to replace. That and not allowing people to copy game saves to an external hard drive so they can push people to pay for their cloud save service.