I wouldn't think of Bézier curves as a design tool, they are more an implementation device. So design comes from some freestyle drawing, and then you implement

I wouldn't think of Bézier curves as a design tool, they are more an implementation device. So design comes from some freestyle drawing, and then you implement it with a Bézier tool to set perfect and minimal curves (the minimal is a property that is important when designing fonts). But to go from blank to design with just the curves can be brutal, yes. There are also the usual free drawing tools which allow you to draw lines freely and then approximate them automatically with curves, but that can be imprecise and murky. The first implementations of digital fonts (before the DTP time with Adobe/Apple/Microsoft) were also using other types of curves, but Béziers won, I think because they are much more efficient to calculate, which was particularly important in the 90s (as the next step after bitmap fonts).