Suppose that you are offered that choice next time buying air ticket.

Would you prefer to have parachute instead of buoyancy vest - just in case ?

I guess both weight and cost the same ( parachute and vest). Small ()modification to air plane should be possible for fast in flight evacuation.
Maybe in next Dream-liner ?
Boenig or Airbus will be first ?

For sure I am tempted to use cheap Air China planes when availabe - and then my parachute concept will be quite handy.

I bet that Air Force One has few parachutes on hand.