The Florida Brightline is limited to 125 mph. Also no grade separation which is needed for higher speeds. Generally countries use grade separation when speeds exceed 110-120 mph. California really needs the 200-220 mph to make the trip worthwhile so it needs to be grade separated. A lot of the work done so far in California is the overpasses over freeways and roads its crossing.

Brightline has had a lot of fatalities due to lack of grade separation.

https://www.miaminewtimes.com/news/death-train-a-timeline-of...