Boeing extended range 767s can reach 6000 miles and the newer 777 and 787 have longer ranges.
If SpaceX can determines ways to save 30% on Starship point to point efficiency then they could get to 8000-mile ranges. This might be possible by lightening landing gear and heat shields. They could need less heat shields for sub-orbital only vehicles.
Going from two stages to one stage will increase the safety of the Starship. Increasing safety by 1000 times is the major hurdle to transporting passengers.
President and COO Gwynne Shotwell, SpaceX could begin offering Earth-to-Earth transport services as early as 2025, if not earlier with Musk's proposed Starship-only variant. This would start with non-passenger services.