Obviously not, but I don't mind keeping a small amount of sats in a custodial account where my fiat bills can be automatically be withdrawn from while leaving 100% exposed to Bitcoin price action at all times.

While you may be more sovereign than I and transact entirely peer to peer with non-custodial bitcoin for every need in your life (kudos to you if so), my alternatives would be either keeping fiat in a custodial account for these payments, or using gift cards, which are equally custodial.