In my setting, the languages are chosen and their mechanics changed to feel real in the world and provide mechanical gameplay
The most common languages on the Material plane are Common, Draconic, and Elfish.
Common or Common Imperial is the official language of the Gryphon Empire, its colonies, it's tributes, and the states and kingdoms which rebel against the Empire. Refined Imperial is used by nobility in court and Middle Imperial by merchants and Sailors. Common is the language you will use in the Central Continent and the Elven one.
Elves live for centuries and before they are freed by their parents or caretakers, most Elves speak Elfish, Sylvan, and Common.
Same with Dwarves. Most Dwarves speak Dwarfish and Common to speak to Human neighbors. Some dwarves hate-learn the language of whoever their King declared war on like Giant. And Giants usually know Giant, Commoner, Draconic, and Dwarfish due to their age and wars.
On the other side of the world, everyone speaks Draconic on the Dragon continent. All the nations are ruled or dominated by dragons, dragonborn, dragoniods, or dragon loving kobold or human cults. So everyone there speaks Draconic as their first or second language.
The only wildcard is the outer planes where everyone speaks their alignment language. There knowledge of other languages is spotty.
So a party really only needs 3 languages to speak with most until level 10.