Is it possible to be a one-guitar guy?
Possible, but unlikely.
These days I pretty much exclusively play Telecasters. But there are times when I think to myself "Gee, I'd really like something with a vibrato system on it," and out comes the Jazzmaster.
Now of course, it is totally doable to buy a Telecaster with a Bigsby system on it for Jazzmaster-like vibrato, but I'm not doing that. Why? Too heavy. A Bigsby on a solid-body makes for an uncomfortably heavy guitar, so that's not doable for me.
The only way to be a one-guitar guy is to sacrifice features
There have been many over the years who have tried - and all failed - to build the ultimate do-everything electric guitar. Both players and luthiers alike have stuffed every kind of mechanical and electronic doo-dad you can think of into a guitar, but in the end, that only leads to an overly complicated mess every time.
If you want to be a one-guitar guy, you purposely have to sacrifice features, play a simple guitar and stick with it; this is why I appreciate Telecaster guitars so much.
Does that mean I will eventually play nothing but Teles? Nope. I'm not about to get rid of my Jazzmasters, because you can't get Tele tone out of a Jazz and can't get Jazz tone out of a Tele. I use both.
I am not willing to sacrifice features to play just one guitar for the rest of my life
Sometimes I want dual-coil pickups, hence why I own a Squier Vintage Modified '72 Telecaster Thinline. Sometimes I want a surf sound, and I have Jazzmasters for that. Sometimes I want country/rock tones and I have the Squier FSR Bullet Telecaster for that.
I'm not saying to hoard guitars, because that's dumb. But I am saying that certain guitars just do certain sounds very well, and the only way to get the sounds you want is by owning those particular axes.
For guitarists that actually are one-guitar guys, I'm envious of them. It does take a real commitment to do that.
Maybe one day I'll eventually settle on one guitar and use only that. But that day hasn't come just yet. :-)