I have an 85mm refractor which I'm happy with but I keep reading about people with multiple refractors of all sizes and I wonder why. What you said makes sense to me - other than a quick Go To, why have a small sub 100mm refractor when you already have 120mm or more? Is this more of a collection thing rather than an astronomy thing?
I think it just sort of “happens”. I first bought an 80 mm. Wasn’t enough aperture to show me the things I wanted to see. Sold it for for a 4”. That wasn’t quite enough, either. Sold that for a 127 mm. Problem with that scope was terrible optics. Really bad cell design in particular. Ended up giving that one away for free to a school. Bought a 110 mm that was the first scope I owned that felt “just right”. Kept that one for several years. Eventually sold it when I happened across a 152 mm that I thought would be just amazing. It was just amazing. It was also big and heavy. I decided to supplement it with an 80 mm. The two together were a great combination. This was the first time I had two refractors at once. The 80 mm had a LOMO lens that was just fantastic. So was the LZOS in the 152. Then I saw some astrophotography taken with a 60 mm TeleVue and had to have that, so I bought it. That put me at three refractors. I was finally stable for a year or two.
After a while, I realized I just wasn’t taking the 152 out any more. It was just a little too much work. I found myself looking for excuses to NOT use it rather than the other way around. I sold it and downsized to a 130 instead. Just enough smaller that I used it a fair amount. But there was still a hole in my telescope lineup... Nothing between the 80 mm that I used for quick looks and the 130 mm. I wanted something with a bit more oomph than the 80 that would be quicker to carry around and setup than the 130. I added a 105 mm on an extremely small, light equatorial mount. That’s where I stand now. 60 mm TeleVue doublet for wide field imaging. 80 mm LOMO triplet for spotting scope duties and airline travel. 105 mm A-P triplet for docent work at my local observatory and most of my back yard observing and for travel to interesting astronomical destinations, and 130 mm A-P triplet that’s used mostly for more serious imaging at moderate focal lengths. I no longer lust after more aperture in a refractor. How did it happen? Gradually over twenty years.