Well in London, I know people mainly in the minimum wage workers and some immigrants from across Europe even end up sharing rooms in a house. So in effect people do buy into fractions of a house..
That room is being rented, not bought, so the tenant has no property rights at all and cannot profit from an appreciating asset, unlike with bitcoin. Bitcoin is a far superior investment to renting.
You also failed to factor in that people on minimum wage cannot afford to rent in London; if they do then they're eating ramen noodles 3 times per day and walking to 3 jobs they have.
Price rises are related to government policy which subsidies housing and gives tax benefits.
Really? Or is the London housing bubble more related to rich/foreign buyers purchasing high end properties in gentrified neighborhoods, either to let out to tenants (see above), or to leave empty and keep as a store of value?