Sorry if this is not the place to ask this question.
I want to note that I am not here to troll or disrespect the guitar instrument, I am just curious about something I was thinking about.

I'll just cut to the point - Why should we need a guitar(any kind) if a keyboard synthesizer can achieve the same sound of every instrument and has pretty much endless options.
Is there any aspect/sound/technique that a normal guitar can achieve that a synth can't?
I even saw people playing a synth and thanks to technology are able to vibrate their finger on the key board and achieve a vibrato effect like on the guitar.
Again, I am not asking this to disrespect the guitar instrument, on the contrary, I really want to get back to playing my guitar and it's something that bugged me.