I haven’t checked the history books but according to this vintage commercial Elizabeth Arden was the first to put blush make up into a pencil form. If that’s true it certainly counts as a make up innovation however there are trade-offs any time you change the form of a product.
If you’re formulating a blush or foundation in its typical form (like a powder or a cream) you can focus on delivering color in the best possible way. That means you’re free to fine-tune the formula to make sure it delivers the right type of color with the right degree of matteness or shine, without too much of a residual oily feel, and so on.
Delivering a foundation from a stick form does provided added convenience but it may cause tradeoffs in other formulation parameters because the product now has an additional constraint: it must be in a solid form. If the stick is soft enough to give you the right payoff when rubbing it on your skin then it may crumble or may melt in your purse. Conversely if the stick has the appropriate hardness it may not deliver color as well.
It’s the job of the cosmetic chemist to balance these trade-offs to create the best possible color make up product while providing the convenience of the pencil form. Yay Elizabeth Arden!