Everyday Astronaut has a good video explaining the reasons behind the Falcon Heavy delay: https://www.youtube.com/watch?v=FOdoNQXQYv8 https://www.youtube.com/w

Everyday Astronaut has a good video explaining the reasons behind the Falcon Heavy delay: https://www.youtube.com/watch?v=FOdoNQXQYv8 https://www.youtube.com/watch?v=FOdoNQXQYv8 It was largely down to the design and requirements evolving over the years. Because the Falcon 9 itself improved and dramatically increased it's payload capacity, it became able to itself fulfil many of the missions that the Heavy was originally intended for. The Falcon Heavy that flew yesterday was quite different to the one that was originally planned.