It is totally ineffective as a currency --- for a long list of reasons.
It's main utility is speculation. But this too is a fraud due to the fact that the speculation is managed, controlled and manipulated by unregulated exchanges which operate without oversight or transparency and with blatant and inherent conflicts of interest in some cases.
The fact that crypto "exchanges" are unregulated black boxes is well known but feel free to look this up too. If fraud is easy, someone will do it. To wit, a case pending in Supreme Court of the State of NY.
https://cryptobriefing.com/tether-bitfinex-must-stand-trial-...
A chain is only as strong as the weakest link and in the bitcoin marketplace, the weakest link is what happens in these "exchanges". Not just my opinion but also that of the Attorney General for the state of NY.