I've been riding long enough that I have seen my bad days re: flats. My tool bags have 2 tubes and a patch kit. If I can find the hole and the repair is straight forward, I patch it. (I want to locate the hole so I know where to look for offending debris in the tire Once the hole is found, patches do a really good job of marking it.
I put only the hex wrenches that bike needs in my tool kit and whatever special tools that bike might require. (Headset, BB and crank tools are ones I do not bring. There's a place for good maintenance habits.) Sometimes and some bikes - a spare spoke or two and a spoke wrench. Leatherman in my pocket for long rides. A lighter, cheaper (and quite inferior) Gerber multi for local rides. (The Leatherman grabs my jersey fabric so I keep it in a cloth bag. Access to multi and keys is much faster with the Gerber.
All my bikes have real pumps.
Ben