Yeah SpaceX will have a very hard time beating the current routes; they're further from the surface and the intersatellite links won't be travelling in a straight line all the time. The best bet is if they can provide those links across oceans that can't be rigged with microwave towers.
The HF radios are transatlantic and transpacific using 10-30 MHz radios. The terrestrial microwave links (several GHz) have been around for a decade, and HF radio is fairly recent. Starlink will have higher bandwidth, but also higher latency.
