It's not so much for now, but in 10 years or so we'll have grandchildren who will be big enough that they will probably want more space than we have.
For now, I desperately need a workshop and a good storage area, and a "hobby room" - probably on the 2nd floor of the workshop. Then I can move my "radio stuff" out of the main house and into the shop building.
A washer/dryer would be icing on the cake, if I can put them in the new building.
The bunkhouse thing is mostly for future planning. If I can do it - great. If not, no big deal because we do have sufficient space in the cottage - particularly if I'm not using up one room with my "stuff"