This is a good topic, we can have several different driving habits and/or conditions. If you putt-putt around town or drive hard can be the factor in getting a tune-up. I used to work at a location that required me to drive on a gravel road for about a mile, behind other drivers. DUST was everywhere so changing the air filter was a regular thing. I just changed out a set of plugs on another car I drive (Mazda 6S) daily. I put 134000 on the original set of plugs but I drive 98% interstate with the Mazda so I feel the plugs will last longer than the G6 which is a daily driver for my wife. Being old school with automotive repair and modifications I rely on the performance of the car to determan if it needs a "tune-up" or just a set of plugs.
Back when, a tune-up involved spark plugs, points, rotor, distributor cap, spark plug wires, air filter, fuel filter and a timing check to name some of the items I changed out.
None, if I want a faster car I'll buy one.