I can name three GCs off the top of my head who have reliable crews. If you have never had any construction work done, you pull up google or your search engine of choice and look for GCs in your area then ask for some references - or just ask a friend?
>When you’re hiring a crew to build one house, what’s their incentive to do a great job? You’re not likely to build another house soon.
Some people just take pride in their work? Referrals? Future work on upgrades to the house they just built? The money to build the house in the first place? It's not like you give them payment on the entire project up front... What's your incentive to put out effort day to day?
>It’s like saying ‘I’d rather have an IKEA table assembled by a person who cares than a piece of furniture made by a craftsman who makes the same table design again and again’.
No, it's like saying I'd rather have an IKEA table assembled by a person who cares, than a pre-assembled piece of garbage from China made of even less actual wood put together by someone working 18 hour shifts in a sweatshop.
I don't know on what planet you think DR Horton is equivalent to a "craftsman who makes the same table design again and again" but that's very much NOT the case with 90% of "big builders" - it's cut as many costs as possible, use the cheapest components possible, and move on to the next one as quickly as possible. Because the average person has no idea that yes, they should be able to plug in a vacuum and a blender at the same time without popping a breaker because it was cheaper to run half the main floor off a single circuit.