My wife is the quilter in the family, and only kept one machine from 1975 to 2006, not counting her one serger she got in 1994 and her one embroidery machine she got in 2001. She bought a new basic machine in 1990, and quickly sold the other one in a yardsale. She sewed up a storm with just one machine at a time for several years.
Then, I started collecting sewing machines in 2006, and now she has so many that it’s sometimes a chore to decide with one to use for which project (37 machines). Several will do the job just as nicely as another. I’m always bugging her to “try such-n-such machine for that project”, just to see if she likes that one better. Life was easier for her when she only had one.
Truth be told; she still only uses 2-3 of them regularly, and a couple more for “special” projects, special stitches, or portability when sewing away from home. Once you get used to a machine that does what you want, it feels good to keep using it. And I believe that swapping back and forth between machines causes you to have to re-train yourself at the beginning of a project. Could be unnecessary pressure in some cases.
I swap around between 3 Industrial machines and 2 household machines (mending, repairs, & construction in a shop), but that’s because they all do different things and it’s not just sewing for pleasure. Don’t feel bad if you like just one machine and it does what you want.
CD in Oklahoma