I have fly fished about 90 days in the last 18 months. I have used a floating line for less than 10 of those trips. Most
of those 90 days have been in saltwater. I have about 30 various sinking lines for use on rods from 4 to 13 wt. Short sink tips, integrated shooting tapers like Rio Outbound Short or Scientific Anglers Sonar in different sink rates, intermediate lines, and full length sinking lines. They all have their places for different situations, depths, currents etc or even how I want the fly to move through the water.
Most of the species I target do not take flies off the surface. I'm fishing from 3 to 30 feet deep.