SLS has the payload capacity to launch orion and a lander for an Apollo style mission doesn't it so why delay Artemis 3 as HLS isn't ready when SLS could technically carry its own lander

Will the Block 1 Crew remain in service years after Block 1B and 2 arrive? As a cheaper option for changing crew on the Gateway and when carrying cargo will not be needed (since crewed versions of 1B and 2 will carry additional cargo on the universal stage adapter).

https://www.nasa.gov/reference/sls-space-launch-system-block-1b/

I don't know if there is a definition for it, but there is something that says "the more you make/do something, the cheaper it gets".

A Falcon 9 (and future Starship) launch is so cheap for the simple reason that they do dozens, (if not hundreds) of launches a year.

For example, the (cancelled) Ares I would do one launch a year, and the launch cost would be about $1 billion. But projections showed that if it did more launches a year, the cost would drop to 1/10 of the original, maybe even less.

And since the Space Launch System will make a launch every 1-2 years, and for a rocket of its class and specifications, it makes sense that it costs almost two billion dollars.

So, since Congress wants the Space Launch System to make two launches a year, it's certainly a very good start in reducing its costs.

Edit: I found what it's called, "economies of scale"

https://www.nasa.gov/image-article/nasa-moon-rocket-stage-for-artemis-ii-moved-prepped-for-shipment/