As a financial advisor: People don't buy bonds looking for stock like returns. They buy them to get a coupon payment of income. Stocks go up on average 8% per year, but you have to sell them to realize the $$$ and be able to spend it (except dividends). Plus with municipal bonds, there are tax exemptions.
I'm not giving investment advice on here, but people at/close to retirement generally don't want to be in all stocks in case there's a year like 2022 or 2008-2009 and you have to liquidate your portfolio at a low point. No one size fits all answers to one's risk tolerance, time horizon, and liquidity needs.
Go Bills!
Almost all stadiums that rely on public financing are funded with municipal bonds.