The way I understand words is they are made up of a dual content—Denotation and Connotation.
Original definitions or rather what is established by common usage, reflects the denotative meaning of a word. Connotation, on the other hand, refers to what many consider to be the evolved definition, made up of a variety of meanings which change depending on cultural differences and other associations people give them.
Denotative content denotes, meaning it expresses an entity that exists outside the mind, not just some creation of the mind or an experience; but something that is discovered in an objective and constant way. Connotation always relies for it's meaning on some individual valuation so it’s subjective.
Take the word—ocean.
This word might bring you emotional responses of tranquility, mystery, or peace. For others like the Portuguese, the word ocean reminds them about their culture's long history exploring and exploiting these bodies of water; but it still means a large body of saline water from ancient Greek.
The way language is created is by using defining certain symbols thereby constructing a syntax for words. If you have studied Latin you can see how logic forms words in English using previously detonated grammar, similar to how computer languages are constructed.
Some may say that objective denotation in language doesn’t exist. Well, perhaps if you try to dissect the root through analysis you can find some sort of indication of this being true, though don't bet on actually seeing the broader truth behind it; I wouldn't be able to.
You'll get caught up in the trees from the forest and forget the entire purpose of language.
Why Communicate?
Master of letters, Cicero understood brevity as the ideal approach to communicating:
“When you wish to instruct, be brief; that men's minds take in quickly what you say, learn its lesson, and retain it faithfully. Every word that is unnecessary only pours over the side of a brimming mind...Plainness of style seems easy to imitate at first thought, but when attempted, nothing is more difficult."
The point of common, everyday-type of communication, is to make sure general relations can be sustained. Things go smoother, conflicts are resolved effectively, and the harmony necessary for people to pursue voluntary means is facilitated.
If anyone can believe anything they want about words, then how are you suppose to settle claims and misinterpretations if you can refer to common usage constantly changing; where is the line drawn?
Some will say consensus.
Relying on consensus may be useful in mechanics and technical applications including blockchain, but something like language, when left with never-ending interpretation, meanings become vulnerable to propaganda which sway the masses.
The fundamental problem with using words solely based on their connotative properties, is that you end up relying on something that is dependent on subjectivity, capable of changing whichever way the wind is blowing at the present time. Without a clear frame of reference in language usage, communication breaks down.
I guess the main question regarding, "why communicate?" is whether precise meanings are even relevant, as for example the word particle, in physics, has a common usage by nonprofessionals compared to those in academia.
It’s essential for the sake of truth for words to have a clear denotative content. The word particle may mean something different to different groups, but without ever any original definition confusion would be rampant effecting scientists down to engineers and the people who benefit from their actions.
The terms liberal, anarchist, capitalism, democracy, race, left/right, and countless of other terms in common usage are used in an imposter manner. So much endless bickering as well as political correctness would stop if people saw such words in their original denotative meanings.