If you talk about using crypto to buy real I don't know if you are specific to Bitcoin, because Bitcoin is a digital asset and money too, whereas Real estate are physical assets, Therefore if I'm holding a portfolio of Bitcoin, Then it makes no sense to using Bitcoin to acquire that property,
Op did not direct the question properly because he did not mentioned only those whom there cryptocurrency they have in portfolio is worth what he is saying because generally there are people who may be just starting and there is no how there portfolio could be use on real estate. However from what he meant after using all your money sold from your Bitcoin to purchase a real estate there will not be any Bitcoin left on your account as an investor, so is a difficult decision because is like selling your investment to buy another without much difference since the both are all investment.