Gold has the lowest amount possible out of all three in your comparison but easy to fake.
Real Estate has the highest amount possible out of all three and will always grow with a steady growth, someone always wants to buy and its getting fewer and fewer.
Bitcoin has the medium amount possible out of all three but you can't and assume the next 15 yrs growth because of the last 15 yrs.
You are correct that past performance does not guarantee future results, yet you still have to decide how you are going to allocate any investment that you are going to make, including if you happen to be a no coiner and you decide to stay a no coiner. that is a decision, and so good luck if you choose to stay on zero when it comes to bitcoin when the most likely better conclusion would be to figure out what your target accumulation level should be, perhaps somewhere between 5% and 25% would be a good start, but hey if you prefer to stay on zero, that's surely your right to make that decision for yourself and your own financial circumstances.
I gues the mate is referring to Bitcoin scarcity and limited supply plus it current values and coverage in the market, of course between bitcoin, real estate and Gold, I will definitely give Bitcoin a higher percentage as an investment and my reasons are that Bitcoin offers me alot of advantages as an investment more than the other two, just like as gold can be faked, and real estate needs alot of maintenance and taxes that suck off almost all the gains, Bitcoin, on the other hand, have none of that, and that makes it truly an edge over inflation.
Secondly, Bitcoin investment doesn't attract any form of tax unless in countries where there is high Bitcoin regulation, but in a lot of other country ine can hold Bitcoin without being taxed or cost of maintenance just like another investment choice, and for that, u may likely give Bitcoin my 50% accumulation target if I have the needed cashflow, because the higher the speed in accumulation of bitcoin, the better and faster way to be in profits on the long run.