If the internet goes down, Bitcoin is rendered useless, you pretty much can't do anything. But I doubt that the internet will ever go down, as in like fully shutdown across the whole world.
I agree. Although not all transactions and activities in the cryptocurrency market are done with the use of the internet; most of the essential ones like trading, investing, keeping holdings are mostly done in the internet. Therefore, if the the internet would go down, it would cripple all activities related to the cryptocurrency market, specifically in the bitcoin market. Although there can be ways to do it offline, the convenience and ease of transacting worlds apart, being it is one of the characteristics of bitcoin would be compromised.