Serious question. Should I have magic in my RPG at all?

Mechwarrior/battletech was wildly successful without magic in the game or story, so why am I hung up on magical abilities? Why shouldn't I just have guns and knives and swords with even more realistic battle rules? Magic seems to over-complicate the game instead of enriching it.

Serious question. Should I have magic in my RPG at all?
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