Of course yes, i will still use bitcoins it stable at around $5000 USD, if it happens bitcoins will be currency because of the stabilised
the users will be mass adoption because they don't fear to volatility of bitcoins, one of reason bitcoins still can't be currency because bitcoins volatility is scary, the people are fear investment in the bitcoins, and I can still get the profit from trading alt coins than trading bitcoins fair fiat money.
the scenario itself impossible to happened , let's don't make an assumption on something unlikely to happened, nothing beneficial. bitcoin price would keep moving up and down maybe the close scenario to this is when the price only move a little bit like up for 1% and down 1% and so on. that's just make trader boring and investors to leave. bitcoin would remain volatile with its decantralization .