Benzene and its analogues undergo electrophilic aromatic substitution reactions instead of addition reactions to the double bonds because:

a.
the carbocation formed from eas reactions are more stable than those formed from addition reactions.

b.
this preserve the aromatic nature of the benzene ring and its analogues due to resonance stabilization.

c.
the π bonds of benzene and its analogues are too hindered and as a result, obstructs the electrophile and nucleophile from adding to the double bonds.

d.
the π bonds of benzene and its analogues are too weak to undergo addition reactions