I wish we had rail, including HSR, everywhere but the real world comes with financial constraints. While a Central Coast trunk alignment would be nice, any reasonable analysis indicates it really should be lower priority than the Central Valley trunk. It's something that would only be built in addition to and after the core system is running through the CV; to add additional capacity, redundancy, and to serve the Central Coast communities.

The Central Valley has millions more people and is projected to add millions more in the decades to come, which matters for ridership and the viability of the system. On speed, the Central Coast is only faster as the crow flies. It may not seem like it, but CV is actually is faster and more direct than the Central Coast on the ground. There's a reason people drive I-5 rather US-101 or CA-1/PCH when doing the NorCal-SoCal trip, unless they're intentionally taking the slower scenic coastal route [0]. There are formidable Coastal Ranges on Central Coast (and much California and Pacific coast of North America) [1][2]. This results in an alignment that is slower and more expensive due to more curves, elevated viaducts, and tunneling. It's also much more vulnerable to erosion, landslides, and flooding. [3][4] CalTrans and local DoTs struggle to keep roads open after winter storms.

[0] https://www.google.com/maps/dir/San+Francisco,+California/Lo...

[1] https://en.wikipedia.org/wiki/California_Coast_Ranges

[2] https://en.wikipedia.org/wiki/Pacific_Coast_Ranges

[3] https://www.latimes.com/projects/la-me-sea-level-rise-califo...

[4] https://www.theguardian.com/us-news/2021/feb/06/california-h...