I think you really harsh realist and I quite agree with you. Bitcoin might well go below 2000$ as well as etherium below 100$. Also I think there will be rail switching towards ripple and stellar.
There is no tangible proof of this idea. I don't believe prices will fall that far. It will stop at these prices for a while and then the prices start to rise again. Worst-case scenario, it'll be back in 2020.
I also believe that Bitcoin and Ethereum are unlikely to fall so low, but I do not rule out that this can happen for a short period of time. Ahead of the New Year holidays, then the Chinese New Year and the lull on the crypto exchanges, at this moment we can see a greater drop in prices for all coins than now, including Bitcoin and Ethereum.