Such trust management schemes usually act like pyramid schemes, which attracts users at the beginning as the early depositors gets payment, and the next and maybe the next. This is done until the project has attracted a huge number of people who are then ripped off if their investment.
As a rule of thumb, treat all options as a scam until it is not, this way you always look for reasons to not invest in a project, helping you discove the holes in them.
Whereas investing in a Fixed deposit would generate a better return. But that doesn't mean I like banks, in fact I hate banks as well.
The problem here is that nobody wants to put in the effort to learn and build wealth. Most of them just want to get rich quick.
Fiat and Bitcoin cannot always be interchangeable, and as an investment options, holding fiat does not generate much revenue, and factoring in inflation, the devaluation speeds up.