Is it really an advantage of being a tall boxer instead of a short one ?

for heavyweights it's a massive advantage.

but in weight divisions it's levelled out. as the shorter guy will have more muscle at the weight and is less of a target.

cheat code is when the taller guy is a massive weight cutter though, which would be offset with same day weigh ins.

 

How often do we see 2 guys with the exact same style and skill levels?
Height is just an attribute like speed. Or like a style. Some guys fight really short(see Sergio Martinez vs Dzinziruk).
IT´s not this huge advantage.