One data point: IBKR pays you 4.83% right now so I think it's quite good. Not the full interest rate but it's a reasonable in my view payment for their service. They also pay you for every day the cash sits in the account. You can also buy any market funds and pay very little for the transaction. Just 2 days ago they also told me that I paid enough in market data refresh request (they are very explicit that those are not free) to afford monthly subscription so they automatically switched me to monthly subscription again telling me it's only for that month so I don't need to cancel anything if I don't want to continue.

Meanwhile my bank didn't even offer any interest on significant amount of idle cash there. Instead they offered me their "currency exchange services" which have approximately 1000x higher fees that what I pay on my brokerage account.

My experience is that my brokerage firm wants to make money but also makes effort to be fair to me. Meanwhile my bank wants to sell me services which are all bad for me. The difference between them is like night and day. The banks are in business of skimming, confusing and deceive their customers.