Shield Bashing can be done with a LMB while raising the Shield. Does Half heart of damage but knocks back the enemy a few blocks.
Shield Charging can be done while raising your shield mid sprint. Upon Contact of an entity it knocks back the entity dealing half heart of damage to Both Player and Entity.
Including these options i feel would give more benefit to having a shield other than blocking and could remove the charge attack that knocks back enemies.
Could also Allow Knockback Enchantment onto the shield.
Allow Pillager vindicators use shields to block players.