Apparently much of the money was in long-term treasury bills, which is only perfectly sensible if you believe you will not have to access that money for 5-10 years.
Not in any meaningful sense if you are only looking to park the money safely and hold to maturity.
Buying 3 month T bills won't pay much, but it will pay more than the interest SVB pays on your checking account balance and importantly is backed by the full faith and credit of the us govt.