I did some major downsizing about a year ago, going from 9 bikes to 3 within 2 months. It felt great and let me focus on changes and upgrades for the 3 I had. I would totally recommend this.

Fast forward a year and I have 4 built bikes and 3 frames in reserve:

-1973 Schwinn Sports Tourer (soon to be converted to flat bar)
-1986 Schwinn High Sierra (period-correct ATB)
-1999 Schwinn Homegrown (superlight drop bar MTB with XTR 11 speed)
-1970s Cherubim 650b Super Tourer that I am finishing building

The frames in reserve are:
-1980s Alps 650b randonneur (made by Toei)
-1980s Toei 650b randonneur
-1970s B. Carre 700C sportif

This gives me a nice spread of functions and represent my interests well. I don't see myself getting another bike for a while.