Better, as well as other online lenders, were definitely offering very competitive financing, especially with the AmEx credit. See this thread for pages and pages:
I took the money and ran. I took the AMEX credit, an employees friends and family discount, and because of a mistake better.com covered a significant moving expense. They didn’t even ask how much it was before covering it. Anyhow, all in the discount was low 5 figures. I closed just before their peak.
I'm sure there was some of that, and maybe it was my location/mortgage situation (maybe they excelled at jumbo loans?) but when I did a full comparison they were "just normal" (some things had moved around on the fees which can make it harder to compare, mind you). Maybe I came a bit after they were tightening (this was just before covid IIRC).
After all, they just resell the loans same as anyone, not sure what there really is to optimize away.