I would not take loans using cryptocurrencies as a collateral. Especially not if I'm expecting to get a property using loaned money because I might end up getting loans for loans rather than paying my first one and owning the coins and a property.
Fiat is more unstable than it looks. If you look at how fiat moved along the years, you'd see that some of the national currencies are falling, some are standing.. but in the end, your money is only going to only keep losing value. I can't call it a safe bet to get loans when you never have the safety that someone will actually rent your place. And when, during a crisis, you won't have the place rented no more, how will you pay the money you owe?
We're quite close to a big, big crisis and that puts real estate under risk. I would actually rather count more on something new such as Bitcoin than real estate because I know that, as a matter of fact, during recessions a lot of people will lose money and have no more budget for rentals.
Now.. why should you purchase rather than borrow? Here's the trick: the chances of ending up with both are actually quite slim! Otherwise, banks would run out of business. When you think about borrowing money from criminals (banks), you should be already contemplating how you'll be able to pay it back not only today, tomorrow or 1 year from now. Are you sure there will never be an unfortunate event until the end of the loan that will make it impossible to pay it back, hence making you lose?
I hate loans. I hate banks, and I will never agree that loans are good ideas tbh. The main tip I have for you is, think about it over the longer term.. is it worth the double-risk? Giving collateral a very unstable asset to borrow money for a property you're not 100% sure you're going to actually own in the end?