Is it a problem if most of all Bitcoin wealth is never used, only inherited? I don't see the problem.
The new rich will not spend much bitcoin, thus avoiding capital gains taxes / sales taxes. The new rich will be predominately young, and will not soon die, thus avoiding estate taxes.
The problem is that tax authorities and popular opinion may seize upon property taxes as the precedent for taxing the new bitcoin-holding rich.
"(2020) A US citizen: Its not fair that I work two jobs, pay taxes and the Winklevoss twins bought bitcoin for $11 million back in 2013 that is now worth $1 trillion - and they don't pay any taxes on it!"