Imagine that the price of BTC reached $1,000,000 USD on January of 2016. The block reward will still be 25 BTC, meaning that every day, 3.6 billion dollars worth of bitcoins is distributed to miners. Miners would be expected to spend almost 3.6 billion dollars per day to mine these coins. That's 1.3 trillion dollars per year, or almost 2% of the wealth produced globally every year (as of right now).
First of all, a probably more relevant comparison would be to the amount of money in circulation (M0), which is ~$10T.
This means, that at 1.3T per year, Bitcoin represents ~13% of the global wealth.
At these levels, governments power are much weakened, and as a result their spending is cut.
Governments typically spend anywhere between 40-70% of the GDP.On top of government, we have financial institutions which coercively trade with our money, without paying dividends.
So we pay 2%, but get smaller and more efficient governments, and shrinked financial institutions in return.
I'd say the saving potential is dramatic.
You assume that bitcoin will replace money , but it's not like that right now and it's not heading in that direction too fast either.
Right now , you can see the bitcoin value more like an oil field getting discovered and explored.
This currency commodity investment puzzle has to come to an end but it won't be that fast.