The problem with Gold, as real as it is, is that most people would rather carry around slips of paper that represent gold promises, than the actual gold itself. There's also significant risk in securing/hiding it if you amase any reasonsable amount.
There is something called safe deposits box and people has been saving their gold for years in banks so there is actually no reason to say that it is hard to secure gold bar. It may not be as easy as securing bitcoin however it is still considered safe so far however the problem with gold will be that you cant really use it as a currency