We can in part. Like you said, it took a ton of time because of environmental review, and that's on the state. With that said, construction didn't begin until 2015, and Trump pulled billions in funding in his first term in 2016 and did the same in 2024.

https://en.wikipedia.org/wiki/California_High-Speed_Rail

If CA had moved quickly, that wouldn't have been an issue, or at least as much of an issue, but because construction took so long to start, it was.