tybin

[DISCLAIMER]I'm not a pilot, I'm an enthusiast with a question that seems to not have an answer elsewhere, that's why I'm here

Hello,
my name's Jake, that's my first post here, thrilled to join the community!

Lately I've watched some paradocumentary about loss of power and it's consequences, and at some point the narrator started to explain that after full power loss (all engines out, only wind turbine/battery power) the airplane is much harder to control because of loss of the hydraulic system (exact words: hydraulics aren't working anymore). I thought about it for a minute and came to conclusion that regardless of having power or not, pilot flies using hydraulics, just that instead of pumps or servos pressurizing the whole system it's his muscles that introduces the nessesary pressure to whole system. Am I right, or in case of hydraulic loss (not the fluids, just the power) he operates by strings, directly affecting control surfaces like in older planes? Plane that's in question is 737-800, but I figured any plane with hydraulic system used to control the airplane would have a similar solution implemented.

PS. If the thread doesn't match the standards or the question should be disregarded as obvoius to people with experience, please give it a chance and move it to offtopic instead of trash. Thanks!