It is my first port of call, most recently how to sew a dress from an online pattern although the pattern instructions are amazing I still liked seeing it demonstrated in a video by a woman who explained it all well.
We have with the help of Youtube; installed bathrooms, tiled, laid flooring, installed a Quooker boiling water tap, re-pointed the patio, cleaned Ds2's computer keyboard by removing the keys, basically any DIY task, any recipe I like seeing someone make it on a video. In case anyone wants some DIY people, Proper DIY, The DIY Guy, Gosforth Handyman and Ultimate Handyman are fantastic and for plumbing, Plumber Parts and MJ Tiff.
I watch youtube to learn about all sorts that I have no intention of doing myself, the wigs of Bridgerton behind the scenes, any Edutainment (Tom Scott, CGP Grey, Jay Foreman) Geoff Marshall and anything to do with trains, stations, the tube, engineering, how things are made, manufacturing, history of anything and everything, Hannah Fry, Jenny Draper and Joolzs Guides - history walks of London. I love Youtube.