To earn interest you should need to make your cash loanable (or allow repo for securities). You either have access and trade or loan them to earn interest.
%% Most likely fine with Fidelity; some may not want to loan a goofy gov with senile risk \stupidity risk \money. Not that it's totally safe, but that's a good sales line+ i really cant argue much with it ,in an election year, which mostly starts in 2024. I made sure to loan the Us IRS a bit more than i had to; if we dont pay all of the estimated federal tax due, promptly\ they fine heavyLOL Inflation risk\ opportunity risk is a small fixed income concern, big bucks or any bucks; but not much for most stock/ETFs trends or private sector business .