There are lots of reasons to have several sewing machines. Acquisitions over time, handed down from family, for different types of sewing, and my OCD - obsessive-compulsive-disorder :0/
I have the Singer featherweight (from Aunt Sandi), Gramma's Singer 66 treadle, a Wheeler&Wilson treadle, a Household treadle, an 1890's Pfaff model B handcrank. A Singer 15-91 that was a $20 garage sale purchase that didn't work, but I dismantled, cleaned it and put it back together - and it now runs perfectly.
My newer machines are a Pfaff Grandquilter on a 10 foot quilting table, Pfaff Quilt Expression 4.0, and Brother 4500 Duetta for sewing & embroidery.
And there are two other machines - I forget . . .