It's true. Scrum was designed with one or a small number of teams in mind. That's why it doesn't scale. I don't want to speak to SAFe - people will think I am a SAFe advocate, but actually I am an advocating for doing what makes senses, irrespective of any "framework".

Complex products often need tens of teams, and those products are often subsystems - "assemblies" - in larger products (e.g., a car or a tractor or a rocket or a phone) that contain tens or hundreds of such subsystem. In that situation, you can't have a fully empowered product owner talking to each team on a daily basis. You need a subsystem product owner; and a subsystem is not always a MVP - it often has not business value of its own, depending on whether it has its own market, or is custom built for the larger product.

SAFe was designed to support large, complex product development. I see SAFe as a collection of ideas - not something to follow to the letter. But it is important to keep in mind the kind of setting that SAFe was designed for, and the kind of setting that the creators of Scrum envisioned.