Yes!
I carry a spare tire in both my vehicles yet I've never used them. I'll carry a spare mag and hope I never need to use either....the mag or the pistol.
Wow. I really thought that was a no-brainer. Would much rather have a couple of extras and not need them than to find myself in a situation where I need them and not have them.
I usually carry only the horizontal magazine holder. It's comfortable and easy to manipulate. The rest is for range training. I also have a few IWB mag carriers if I really want to get loaded up.
Slightly longer answer is God forbid if I ever have to shoot even a single shot, every trainer I've ever worked with has advocated that as soon as the shooting is over the first thing you do is reload.
In real life this has only ever happened to me once but it did happen. I got to work one night and as I stepped out of my car the magazine fell out of my gun and bounced off my foot. I don't know why it happened but it happened.
In that particular instance I picked the magazine up off my foot and put it back in the gun. Had it fallen out in the grass somewhere where I didn't hear it hit the ground I had my two reloads as dictated by company policy
ALWAYS, at least one, and depending on what I'm carrying, one extra is the minimum, for the carry gun.
The truck gun on the other hand, one close, and seven spares......
I live a sedate lifestyle in a rural area. My EDCs are 11+1 and 15+1. I have spare mags in the truck and a 19+1 Glock with spare mag. So unless on a road trip, no extra mag for EDC.
Carrying a spare mag isn't just about extra capacity - the mag is one of the most common reasons for a malfunction. In that situation, I'm not going to be problem-solving, I'm going to be dumping the faulty mag and throwing in a new one.