[stu2010]

Many states still only require $15,000 of liability coverage to drive, so there's going to be a lot more uninsured / underinsured motorist claims in the future.

The Rivian owners insurance will frequently end up paying out, via that underinsured motorist coverage.

[smileysteve]

To detail, though the Rivian driver has under insured insurance, the at fault party is still responsible for that difference, and the insurance company will take the at fault party to court if they can recoup a portion of the remaining $35k at low expense.