It's not entirely fair to compare bank failure sizes across times, even inflation adjusted [1]. The rate of asset price growth since 2008 far outstrips inflation.
IMO the frequency of bank failures is more worrying. They tend to come in waves [2].
1: On the size of bank failures: https://yarn.pranshum.com/banks 2. On the frequency of bank failrres: https://yarn.pranshum.com/banks2
> Most banks hold more assets than deposits. So in theory, depositors should always be made whole.
No such theory is established; it's the central bank's money printing ability that can always make depositors whole. In the US, the Federal Reserve implicitly backs the Federal Deposit Insurance Corporation.
The FDIC holds an adequate deposit insurance fund, financed by banks who must buy FDIC insurance. It's over $100 billion dollars, which is enough to weather some major failures. With large failures, the FDIC may issue special assessments to maintain the fund at a safe level (they did this with SVB).