In partial reuse mode, you get 57k kg from Falcon Heavy vs 95k kg from SLS, with the catch that you can launch 25 Falcon Heavies for the same cost as 1 SLS. And that's exclusively the recurring (and likely greatly low-balled) per-launch costs, ignoring the tens of billions of dollars that have (and are) being dumped into its development. In reality those also need to be aggregated into its cost per launch.
Orion's mass far exceeds Heavy's payload to TLI. It simply can't be used for the Artemis manned lunar program unless you want to completely reengineer the entire thing.
This is incorrect. NASA even carried out an internal study on this exact topic. [1]
Everything NASA does is trying to shoehorn in Boeing one way or another because they have tremendous political influence, but there's really no reason for them to be involved at all from a technical point of view. And in fact if they weren't, then we indeed probably would have long since already put boots on the Moon again. But because they are involved, I suspect an appropriate timeline for success is: never, with a whole lot of money spent getting there.
