The hydraulic needs the engine going or a power packs to be on to have power. An electric winch will also need the engine pretty soon or the batteries will just run down. The main advantage the electric would have is a stalled engine in a river drowning say. A hydraulic will on other occasions just run all day non stop as long as the engine has fuel. Multiple recoveries are no problem at all. Thousands of feet. You of course would have to rewind as spool lengths are limited of course but that is the same for all winches.