Monero is technically superior to Bitcoin in a number of ways, but it has one major flaw that cannot be addressed.

While there are no known bugs in the code, if an inflation bug were to be discovered and exploited, it could remain undetected for months or years due to the opacity of the ledger.

Correcting this flaw would necessitate compromising some of Monero's privacy features.

So while it's very useful for spending privately, it's a very poor choice to denominate your savings in, since you must logically assume that an inflation bug already exists and is being actively exploited.