Decentralised exchanges will rise at the same time as centralised exchanges run by competent and regulated operators. It's getting there on both fronts but not quite yet.

For better or worse most will flock to the places that hold their hands. At the same time they'll drive out the people who are either dodgy or simply wish to remain close to crypto's original intentions.

In that case they'll be widely used but never fully mainstream. I think they'll be the decentralised Linux to the centralised Windows.