Over the decades, 6.8mm / 270 has on more than one occasion been identified as the ideal military bullet diameter based on ballistics (internal, external, and terminal). The 1950 British Ideal Calibre Panel looking at what proposed new assault rifles should be built around initially chose it, but went for an intermediate size 7mm in the end, the 280/30 aka 280 British or 7X49mm. I'm sure that an interwar US rifle design to replace the 30-06 M1903 also used a 270. I thought it was the Pedersen automatic rifle, but research shows it as a seven. Then there's the 6.8mm SPC which seems to have died after minimal use.
However, that was then, and in the 2020s, there is so much experience with 6.5s and 7s and in successful bullet design, I agree that 6.8/270 has to be an absolutely perverse choice now. And that's before we get into the other aspects of this strange cartridge design which defy every known bit of empirical military experience and common sense that say build on what we know works allied to KISS (keep it simple, stupid).
To me, the whole saga is reminiscent of the millions of D-Marks and years of R&D resources H&K and others spent on the caseless cartridge / G11 rifle saga which in the end produced nothing militarily usable either by that company or anyone else.
