Interactive Brokers offers 4.33% for cash above $10k. They have a very easy model of "benchmark minus 0.5%": https://www.interactivebrokers.com/en/index.php?f=46385

Insurance is $2.75M but IBKR isn't a bank and isn't subject to the same problems in the same ways (e.g. bank runs).

Wealthfront offers the same, but with 4.3% and $3m insurance

https://www.wealthfront.com/cash