Currently, the only way to travel between the islands is by actual airplanes, through airports, with all the annoyances that comes with that, TSA, security, bag checks, prohibited items, and a gazillion other rules. That's what this thing will compete against, and it's pretty much a slam dunk.
Unless it will be lobbied to death like the predecessors.
There were also a lot of environmental protests against the Superferry that I doubt can all be chalked up to car rental and airline lobbying. https://en.wikipedia.org/wiki/Hawaii_Superferry
If they're keeping TSA for intrastate flightd it's just as a fed funded voluntary jobs program for low IQ undereducated people to not have to rely on state welfare .
I have done an inter-island flight from smaller small prop plane terminal in Kona adjacent to the main (but still small) terminal and I'm guessing I didn't have a security screening in that case.