(non-native speaker)
Is there a reason why the English language has “special” words for a specific topic, like related to court (plaintiff, defendant, warrant, litigation), elections/voting (snap election, casting a ballot)?
And in other cases seems lazy, like firefighter, firetruck, homelessness (my favorite), mother-in-law, newspaper.
It really depends on how the vocabulary got to the language.
First, you have to start with the fact that English is a Germanic language with a lot of French words in it due to the Normans. A good example is that farm animal names have a Germanic origin typically while the words for meat have more French origins.
You can also combine it with the fact that English was rather varied in its vocabulary at the time. An example is eggs/eyren. Egg won out as a word, but there were likely thousands of these decisions being made as the language standardized.
Then, include that a lot of legal and religious terms came from Latin; with the practices using Latin far beyond when English became the dominant language in England. So, for these fields, just use a mangled version of the Latin root.
Finally, it depends on how a word enters the English language. Maybe it comes from another language, so we just use a version of that word. Maybe the creator of the word just makes something up. Maybe the creator just slapped a word on something that wasn’t typically used; the wiki from Wikipedia comes from the name of a Hawaiian bus.
It is a strange, made-up way of naming things, but language itself is made up thing.