SAFe killed agile first :)
From my experience it depends on the company culture, leadership and the way agile is implemented and started with in a company.
Big companies with very old and complex architectures coupled with old school separation of business and IT and a bag of bureaucracy. Will properly need a PMO, or SAFe like implementation. Sometimes they are in luck and they are able to start with departments or a business units and move faster. But even if you have that the wider organisation will lag heavily. Most if not all can't become agile in an instance with implementing the perfect agile way of working. Even transforming to an agile organisation is best done in an agile way.