Why should we have a lot of programming languages instead of having a single all-purpose PL? Is it possible?

Question

I mean we all know a lot of PL like C, C++, Java, etc but why isn't there a language that can be used for all platforms development?

Answer 1

We can't have clothes to help protect us against winter,summer,rains,animal attacks or falling from buildings.But may be possible in future

Answer 2

JavaScript :)