The reason for (2) may be the following: can the company verify that the candidate did in fact work at Google for 10 years and reached L6?
I don't know about Google, but if someone claims they worked at Microsoft as an L65, and they call Microsoft to fact-check, Microsoft will only tell them when that person started and ended their employment there. They will not disclose any other information.
> if someone has 10 years of experience at google and is L6, why do they need to do the standard process to work at some rinky startup?
The startup doesn't trust that Google's process is absolutely infallible, presumably. For good reason, probably; a bad hire is much more of an existential risk for a small startup than for Google.
1. if i got an offer from your company a year ago, why do i need to redo the phone screen and entire process?
2. if someone has 10 years of experience at google and is L6, why do they need to do the standard process to work at some rinky startup?