Strong inflation of the FIAT currencies which is happening right now and accelerating would also multiply the nominal value of Bitcoin over the years. If real inflation reaches more than 20%, which it will, we are looking more into 10 million USD per BTC in the best case scenario within 10-20 years.
But full adoption is not a certainty of course. However, even a 5% adoption can bring the value of bitcoin to 100 000 in the next few years.
100K and 1 mill are simply arbitrary values with no meaning without mathematics. I simply said 100K because OP was assuming that those with 10BTC or more would have at least 1 mill and I gave a scenario that I was fairly sure would suffice. I doubt anyone would be capable of actually estimating the value of Bitcoin given a specific number of people using it on a day to day basis. For all you and I know it could be 10 million.
I'd tend to disagree with that statement - it seems to be a bit exaggerated. Do you have any maths to actually suggest a USD$10million value in that timeframe?
The math is quite simple.
The Gross Global Product is a bit more than 50 trillions USD today. Let's take pessimistic views and let's assume the Gross Global Product to remain constant in real terms. If we assume a 20% real rate of inflation over the next 10 years, it would be 300 trillions USD in 10 years (USD would be worth 6 times less in real terms).
If BTC reaches full adoption (which is of course a very optimistic idea - and what does it mean exactly?), we can take a very conservative approach and estimate that the market cap would need to be about 50% of the annual gross global product, so 150 trillions USD.
If we assume that the total number of BTC in existence in 10 years will be around 15 millions, we have a very simple calculation : 150 trillion / 15 million = 10 million USD.
Of course these 10 millions would be worth "only" 1.67 million USD in today's real purchasing power.
But in such an optimistic scenario, I believe that the figure of 50% of the global GDP market cap would be too low. Most people would be keeping their wealth in BTC as opposed to FIAT, treasuries and stocks due to the real inflation. So we are looking more into a market cap of 200% of global GDP which would be 600 trillions USD in 10 years or 40 million USD per BTC.