Every job is different and therefore requires different tools to do the work. For example, a regular household hammer is not built or strong enough to work on a structure that is made of steel. Or that cheap set of tools you just bought to fix your shed door would never stand up against a bug high rise building structure. Big jobs require tools that can do the job that needs to be done.
Big industrial type jobs also require that you meet deadlines and this would be impossible with a little household saw or hammer. It would take you forever using these types of tools. So you need the big industrial tools that can keep up with the fast pace the job requires.
Never start a job without being prepared for it. Make sure that you have the industrial tools you need to get the job done fast and done right the first time.