Airbus designs are substantially fly by wire, although supposedly with an isolated control system. Boeing designs are isolated electro-hydraulic.

There's a big difference between isolating a single control link vs an entire control system comprising of, at least, a corpus database and all the supporting code that streams inputs and actuates outputs.

I assume / hope that there still exists manual hydraulic controls for the control surfaces. Maybe not in the cockpit, but somewhere accessible in flight in an emergency.

Modern U.S. submarines are also fly-by-wire, but hydraulic overrides are in the engine room in case of emergency.