If all people did was simple equations like the one in the OP, you’d probably be right, but math syntax has to deal with all kinds of equations. Your way, I can’t write 3x^2–4x+5. Instead, I’d have to write ((((3x)^2)−4)x)+5. That’s WAY more obnoxious. It’s better to have an unambiguous syntax that covers all the cases and lets me write equations in an more simple form.
If all people did was simple equations like the one in the OP, you’d probably be right, but math syntax has to deal with all kinds of equations. Your way, I can’t write 3x^2–4x+5. Instead, I’d have to write ((((3x)^2)−4)x)+5. That’s WAY more obnoxious. It’s better to have an unambiguous syntax that covers all the cases and lets me write equations in an more simple form.