[Staple_Diet]

Who were the existing providers in the space/rocket industry? NASA and their foreign counterparts?

Shipbuilding is much larger. Shipping is a huge industry with many parts. It is not necessarily impossible for a new company to come in to any single area, but they wouldn't be able to break into something like military ship building.

A possible avenue for 'disruptive startup' is the USV area, see Anduril. But even then that required immense amounts of capital because you are competing against the big dogs (Raytheon, Northrop Lockheed, Boeing, BAE etc.)

[Perceval]

The existing providers were NASA and United Launch Alliance, the latter of which is a joint venture between Boeing and Lockheed. They merged their space launch businesses in 2006, because neither could individually sustain their launch services given 1) the expense of their systems, and 2) the low number of launches in the late-90s/early-00s. They were the sole provider to the USG from 2006-2015, only because SpaceX won its lawsuit against the Department of the Air Force in 2015, which had been blocking SpaceX from competing for DOD/NRO launches.