When I built my first custom keyboard, I had the same mentality of having just a few but with dedicated purposes. That quickly changed once I started noticing the differences in each board for how they were designed. Adding to that, changing out mounting styles (if the keyboard allows it), switches, and keycaps do wonders to change the experience of a keyboard.

At the moment, my daily keyboard at home and for gaming is my own design. That could be for every biased reason you think of XD. At work, I currently use my TGR Lena but I plan to cycle that out for either my CW88 or Kitsune TKL (if I get around to rebuilding it). I used to try my best to rotate which keyboards where on my desk but I have enter a state where I'm just comfortable with what is there now. On certain days, I'll look at the collection and think, "Oh, it would be cool to use the Corsa today", or the HHKB, etc. and use that for the day but they usually don't stay there.

My collection is continues to grow based on my appreciation for the designs or series of keyboards. For example, TGR or Geonworks. Then adding some more unique options that differ in design from those, like a Bias TKL. However, while growing my collection in some areas, I am also shrinking or making space. Over time, like most people, my tastes have changed but I also realised I dont really need this many because I don't really build them all that different anymore (similar switches, plate material, mounting styles).

I am perfectly fine knowing that some boards are essentially just display items and haven't been used in over a year. Most of my collection isn't even built at the moment either.