One possibility of this happening is almost everyone coming on bitcoin and using it for transactions or storing their wealth. But this doesn't look practical as we already are facing a hell of lot of scaling issues with huge fees along with that. If we expect the value of bitcoin even at 100000$ we are talking about fees of more than 40$ per transaction which is insanely high. Until we can solve this issue I don't think we can grow that high. Alternative chains and Lightning Network might help a bit but everyone knows that they don't really offer a great solution to this problem. But yes 200 Trillion is a pretty big number even the whole US GDP is about 20 Trillion $. So 10 Million is quite an unrealistic number we currently aren't even 1 Trillion.