Oh, dear. This shibboleth has popped up again, but why not, it's Christmas...
I grew up in an era of photo-minimalism. In the 1950s, most people could only afford one camera, and even with film at 50 cents a roll or often less, a few rolls every year, usually to shoot groups of family or friends lined up in self-conscious lines in front of the camera. Most photo albums are full of these static images. As are trash bins after the photographers pass on.
Thankfully, we no longer have to indulge in such parsimony. Nowadays almost all of us can afford good cameras and additional lenses, thanks to discount camera stores, charity shops or Ebay. The price of film has gone up, but then so has our disposable incomes.
We have the luxury of choice. If one wants to go out ad shoot with only one camera and one lens, so be it. I have no wish to be the grinch in this thread. But to me, to try to do this over a year smacks of masochism.
Fortunately, most of us would give up this little game long before the twelve months have passed. A few will persevere. Whatever one's choice, I reckon the resulting images will be about equally good, with some quite superb from both camps. Which is really what good photography is about, not the choice of gear.
When I go out shooting, I take one camera and three lenses. Let's say my Contax G1, which I regard as one of the finest and most often maligned rangefinder cameras ever made. I usually carry a 28, a 45, and the also greatly criticised 90. (I also have a 21, but it usually stays at home, also a 35-70 which I bought before realising it works only on G2s and not G1s, never mind). Often as not I shoot only with my 28, but that's my choice. The other lenses are there if I need or want them.
Lest I be accused of trying to spoil everybody's fun, let me say I've written the above purely as my own opinion.
Do try to get out and shoot images with your one camera and lens or your many cameras and lenses over the coming end of year break.
To all of you, my best wishes for a happy and safe holiday period.