T Bill rates are decreasing rapidly and likely to continue to do so. However you are correct there is a spread you can potentially capture. The possible pitfall of that strategy is you likely have to wait at least 3-5 business days in ACH transfers and if there’s a BTC price move during that time you could miss it. But even that depends on when the TBill redeems versus when river pays our interest.

Think ur missing the idea of convenience for most people. If the extra 1% is worth the effort for you then more power to ya tho.