The most successful agile frameworks describe small delivery teams working collaboratively and delivering little and often. They are discovery-based and adaptive. They favor customers represented by a single individual (product owner) and business value being the driver for work selected and delivered. On a small scale, they are all you need to succeed.
However, as the scale grows… multiple customers, multiple teams, more effective products and broader goals and objectives… they do not offer any way of managing these challenges. This is the environment that PRINCE2 was built for. A way of working that decides what projects to do, sets up the environment for success, regularly checks that a business justification for the work exists and continues, escalates significant issues, reports progress to senior management and coordinates multiple teams working.
Bring both together with a strong emphasis on “protecting the delivery approach from anything that will make it less effective or efficient.” You can have the best of both worlds… Demonstrable governance and effective delivery.