Most programming (simple tasks, scripting data analysis, most common web apps, basic automation) is about as difficult as doing your own plumbing (which likely includes fixing a faucet or doing other minor tasks around the house). But just like in any profession, the “professionals” are able to handle the complex tasks that others can’t/don’t want to do. For plumbers that means building the whole home systems to maintain proper pressure/temperature at every outlet, suitable for whatever climate the home is built in, or in commercial settings where the systems are much larger and more complicated.