When you see the entire stock market move because the Fed chairperson makes an offhand comment about when they'll start or stop doing xyz policy, you realize having such a highly centralized system is dangerous.
How your investment porfolio reacts to a change in monetary policy has nothing whatsoever to do with the utility of your checking account.
Trust in centralized financial institutions is not a problem. In fact it's is the opposite of a problem, it's an enormous benefit. Centralized financial institutions with government backing ensure the availability and safety of deposited funds.
Nobody has ever had their bank account drained in the US since the introduction of FDIC in 1933. In the last 10 years alone, over a billion dollars in bitcoin has been stolen out of people's wallets by hacked exchanges and smart contract exploits, money that can never be returned because blockchain is irreversible by design. Does that really sound trustworthy to you?
Plenty of people have had their bank accounts drained when they fell victim to "identification theft." That is quite a crafty euphemism -- banks fail to create secure systems, attackers steal funds from victims' bank accounts, and instead of owning up to their failure, banks blame the victims of the thefts by saying the victims' "identities" were "stolen."
I'll give the banks some credit, however: they'll prop up a seemingly empathetic customer service representative who will repeatedly say how "sorry" they are on behalf of their employer. If the victim is persistent enough, the customer service rep will eventually promise to initiate a lengthy investigation, after which the bank will perhaps reinstate the funds that were stolen from their system. Do they fix their broken, insecure system? Of course not. But at least the victim isn't clogging the customer service lines any more.
What happens if your bitcoin details get stolen, hm? What happens when somebody drains your bitcoin wallet? Who can you complain to to get your cryptographically secure irrevocably transferred money back?
Some people are fine with that risk. Others are not. It's totally cool. More than one value transfer system can coexist in the world.
These are all reasons that banks are more trustworthy and more secure than blockchain, which sees tens of millions of dollars of irreversible theft annually.
I move USD from my checking account into my investment accounts in order to buy equities, and I do that more when the Federal Reserve is pumping more liquidity into the market via low interest rates. There are many folks out there using e.g. TSLA as an inflation hedge (which is why it has a P/E > 1000) because they know that USDs will decline in value as liquidity keeps getting pumped.
If we're all using a decentralized currency like Bitcoin with a fixed inflation rate, you're going to see a lot more sanity and price stability in the equities markets.
Then you see that Bitcoin moves more when Elon tweets...