Your post sounds ignorant tbh. Yes, been through a few recessions. Bear markets do come. The premise of fire and the trinity study is that we have backtested data that goes back decades that shows an equity heavy diversified portfolio beats inflation in the long run and has a higher chance of success than bonds or short term instruments. In a FIRE compatible allocation, you do hold some amount of fixed income to manage risk but it is not the majority of your portfolio. I would like to see the data where a diversified equity portfolio (e.g. total market index fund) lost value over a 30 year period but fixed instruments did better in that same time period. Will be waiting.
If you want to pay someone 50bps to underperform over the long term and be subject to inflation eating away your portfolio, it’s your money. But if you have not read the trinity study, you don’t have any business talking to people on a fire sub about asset allocation and risk IMHO. How do you think your 7MM in cash is going to do once interest rates reset?