I'm at 12 instruments total. That includes 10 electric, 1 acoustic, and 1 bass.
I did start the year with 13 but I did a massive overhaul of my gear this year and sold/traded off a bunch and bought new stuff that better suits my current tastes.
I could definitely sell off a couple more and be fine. But I don't want to. Also three of the guitars I have are very specific to the type of band I'm in. As "Keith" in a Stones tribute there's some guitars that serve that aesthetic and sound. The 52 Tele in open G - a yellow LP Jr DC - a white Music Man Silhouette HSH.
But I am at a point where I do not want to increase the number that I have. I'm on a "one-in, one-out" rule. Not imposed by my wife or anything like that, but it's something I've applied to myself to keep my "collection" in check. I found once I was above 12 I really started to feel like the collection was a weight on me rather than something I enjoyed. Plus the amount of time I have to spend maintaining them all - string changes, setup tweaks, seasonal adjustments - it's kind of time consuming which I would rather spend on playing. So if I've got GAS for something, I have to sit here and take a long hard stare at the guitars hanging on my wall to decide which of them would go.