Doing basic drywall and paint isn’t rocket science, but getting a professional level fit and finish actually takes a lot of practice and experience. It’s also a completely different experience when you’re trying to match old specialty paints from a previous homeowner, blending repairs to match the wall texture, and other complexities that don’t show up in those basic YT videos. If you’re in a situation with untextured walls, known paint colors, simple repairs, and a forgiving eye, then it’s really not bad, but the complexities can add up quickly.
Even in the best cases, cutting into drywall all across the house to pull wire would be a project I’d try to avoid at all costs in an occupied home. The fast path still requires multiple days to go through all of the drying and re-application cycles to build up all the right layers, not to mention dust control to keep that fine dust out of everything you own.