You're still mixing different time period sizes in 1. I think even size adjusted per ride, Lyft may still be in a better position. 6B vs 750M (more if using newer numbers) when the market ratio of Lyft is nearing a third means that unless their yearly losses are over 2B, they still have the edge.

Overall I agree somewhat, but when what matters is explicitly runway (who can survive the longest), scaling for size may not make sense. Lyft's smaller current size might actually advantage them in this marathon.