this at least has real links to tangible asset worth,

Well, kind of. But the worth of those assets is largely due to perception, rather than real utility value. Like, real estate is stupidly expensive in many places, but it’s expensive because people believe that it’s expensive. When real estate bubble burst, you see the ‘worth’ of that real estate drop sharply. The utility value is having a place to sleep, but it’s often treated as an investment. So you would still see currency value fluctuations. Currency issue by gov’ts largely has worth because the gov’t says that it has worth; it’s not tied to anything. (BTW - tying currency to a tangible asset limits your ability to add currency when necessary. It will tend to lead to depreciation–the value of the currency rising–which is usually a bad thing.)

The other problem is that corporations and banks go bust; if they were issuing currency, that would mean all your money would instantly be worthless.