Engineering wise the problem with electric is that electric motors run fast with low torque. Yes you can gear
them down but you're starting with high RPMs, especially with DC motors, and several choices of speed/torque curves that are difficult to work
around. Typical winch motors are DC shunt wound and the problem is that the starting/stall torque is excessive and will break things. They also give off heat and are inherently difficult to seal completely, and are big and heavy.
Hydraulics, at the winch end of things, you have a lower speed motor
that has relatively forgiving startup properties, is easy to seal, is self cooling
(at the winch), and will stop without damage when overloaded. And they are small and light compared to electric. There's a catch. You have to have an HPU to run them, and another set of troubleshooting skills, parts
, and tools.
If you have an HPU that just runs when a winch is turning it will maybe use 50% more power than an electric winch. I'm guessing. But not a big difference because they run so little in terms of minutes/hours a day.
There is a certain minimum size of the HPU, lines, valves, controls, etc., which means that they only make sense on larger boats. On a big motor trawler
or whatever they will tend to be engine
I used to farm and worked on more hydraulic gear
than you can imagine. Not a big deal but another basket full of adapters, gauges, hoses, etc. The hoses and seals
all fail progressively over the course of years. You can either spend the $$ to replace them early or have them blow at the worst possible time. I did some of each.