Considering the supply vs global population = 0.003BTC per person to go around.
Then other factors like not all 21 million will be in circulation due to lost wallets/deceased hodlers who never informed anyone where their seed is, and also an increasing global population and future generations who all want in.
Do you think 0.1BTC will be like owning a mansion?
Though question because bitcoin would need to rise a lot to reach that levels. Let's say a mansion costs 5 million, that means the price for 1 BTC would be 50 million USD. That's a lot compared to the 50,000 we are at right now. Maybe in a few lifetimes this could happen, but not any time soon. First of all we need to reach the 100,000 which would make it possible to buy a cheap home for 1 BTC. Long term it still remains to be seen if all countries are going to accept bitcoins. If the ban on cryptos is going to be lifted than it could eventually happen. There is no upper limit for the price of Bitcoins.