Can I use the same foot for all sewing jobs

Why do you have a variety of presser feet?

Each foot is designed to be the correct tool for the job in hand. If you look at the feet supplied with your machine they all look quite different - metal, plastic, zips, spikes and prongs for over edging, and so on. If you use the correct foot for the job / technique that you are stitching it will be quicker and more efficient.

Would you try to tighten a screw with a spanner? No! So don't try to put in a zip with a zigzag foot...