In the field of unreal and relative(pannatti)we use the terms-man,woman,dog,cat etc.
For example you have a user name-Hanzze.I also have a user name-Nanadhaja-This identifies you and me in an unreal and relative way.
The other day you sent me a PM to ask a question.Suppose all of here instead of using pannatti decided to use the terms of real and absolute(paramattha)
Your user name would be rupa,my user name would be rupa and all the other peoples names would be rupa.
How would you know which rupa to PM and how would the rupa that received the PM know which rupa had PM'd them?
So you see it is necessary to speak conventionally.
In Cambodia when you go to a stall to get some food and you want a bowl of noodles,you ask for a bowl of noodles and they give them to you.If you go to the stall and say "Rupa would like a rupa of rupa"my guess is that Rupa will start to feel a bit like a peta.
And crawling on the planets face,some insects called the human race.
Lost in time
Lost in space