You can trust both!
You dont need to choose since both things can really be possibly for you to engage on without needing to focus because you do really need both specially fiat.
Even if we do hate up centralization but still we are heavily dependent in fiat and other centralized institutions and we cant really deny such thing.
Dont focus on one because even how hard you do believe on crypto, fiat would still remain no matter what.
We think that fiat bank is more safe and reliable since it has centralize control but still its not 100% secure. Like for example we have a big holdings inside the bank and unluckily time comes that the bank declare bankruptcy then sadly we cant claim all the money we have on that bank. Unlike crypto that is decentaralized we have all the controls and mostly has bigger chances to gain more profit on our long term holdings.