Re: The more I hear
I don't think the effort will be wasted, but NASA seems to have been hamstrung by politicians specifying SLS detail. Or just arguing for a favorable distribution of pork. A better way would be the Trump-ish 'Boots on the Moon!' to just specify the objective, and allocate budget. Then NASA would have a free(ish) hand to make it so.
But then there's physics. NASA's done this before and knows if the Moon is the target, and payload is X, then we need a BFR. A lot of energy is needed to escape gravity, so that means thrust, which means fuel, which means mass.. So borrowing the idea of strap-on SRBs from the Shuttle programme makes sense.
But there's also been the problem of the US not really investing in space programmes, so kinda lacked a decent engine for heavy missions. But that's also a physics/engineering problem, ie if the old Soviet engines are good enough for government work, why invent the better mousetrap? And then politics intervened, limiting availability of those engines.
On the plus side, there's been competition from SpaceX, Blue Origin and others.. Which includes Russia, India, China etc in a possible repeat of the space race.