Continents and vowels are a consistent set of symbols for sounds which has been built up from pictures to diagrams to symbols over a period of thousands of years. It is a way of converting spoken language to graphic communication. My view is that as long as these consistent patterns are noticeable in a typeface, then the artist can be as experimental as they want with the text.
Johanne Gutenberg printed a bible using wooden letter press for the first time in 1436. This shows that influence for movable type was to spread the word of religion. From this point the amount of typefaces being created drastically increased as we no longer required hand written methods for mass producing type. However, it was still only the wealthy and religious scholars who could read written language and it wasn't until William Foster implemented the elementary education act in 1870 that the rest of the population started to learn the alphabet. This boosted the need for written language even further and solidified it as it as a significant part of modern culture. As can be seen on the timeline below, type increased drastically during the transitional period into the modern era.
This is where the modernist view of type started to be theorized where people were looking at the function of type instead of the form. Culture moved away from the decorative handwritten typefaces and started to strip type down to its bare bones in its simplest manor. Then the creative craft movement Bauhaus met with mass production between 1919 -1933. This moved type into lead printing of text onto a mass scale. Through this Max Miedinger invented Helvetica which was born out of the necessity for clean clear industrial concise type. This could then be mass produced to be the most functional font in history with its involvement with street signs and subway systems. Helvetica is the birth of modern type which then heavily influenced other typefaces such as Ariel which was released 25 years later by Microsoft in 1982. In 1990 Steve Jobs. released the first apple Macintosh. This would become the first computer to sell for less than $1000 in 1990 which made it affordable for designers on a mass level. It also introduced a mouse with a computer for the first time which made it available to work with vectors on screen and again boosted creation of typeface into the 21st century.