As long as there is money in other investments it can grow. Basically crypto gives people another option to invest in and some of them are taking their money out of traditional investments and putting into crypto. The limit is literally the total market cap of investments world-wide, but it will take a few decades to get there. I don't think that it will be 100% crypto though.
I dont think people will take their money from other investment and put it in cryptocurrency without knowing and believe.
So we need to introduce at least to our family about this. If they beloeve then they will put their money here.