They were really good, but to be completely honest up to the 30's and in some places even later, making one was very expensive so they weren't designed to be disposable. Any really old sewing machine is BIFL for multiple lives of home use. Industrial or tailor grade machines were of course on another level again...

What I mean to say, an old Pfaff or Bernina weren't any worse, just less mass produced and less widely known.