One selling point for the cleric is that it is a front-loaded class. Other than the 17th level domain feature, a 10th level cleric has all of its class abilities. They have all of their bread and butter abilities like Channel Divinity, Destroy Undead, Divine Strike (or Potent Spellcasting), Divine Intervention, and important spells like Greater Restoration and Raise Dead, Banishment. That means that in most campaigns the cleric gets to play with all of their toys even if they never see tier 3 or 4. Also, in tiers 1 and 2, domain spells give clerics more spells prepared than any other class which means that they have a better chance for having useful magic for a situation even if they don't have big damage spells.
The experience of playing a cleric depends on the role of gods in the campaign. In the DMG the first default core assumption for D&D is "Gods Oversee the World...Gods exert influence over the world by granting divine magic to their followers and sending them signs and portents to guide them. The follower of a god serves as an agent of that god in the world. The agent seeks to further the ideals of that god and defeat its rivals." Playing a cleric is more fun if being an agent of a divine being is important to the campaign, and the player gets occasional portents and minor gifts that reward good role-playing. I think the satisfaction of playing a cleric depends on role-playing relationships and motivations more than other classes. Without them, then they could very well feel generic and boring.
Give a cleric minor magical gifts that reflect their god's favor when they reach certain levels. eg at 2nd level, "Thor is pleased with your bravery in battle, and your warhammer is now blessed. One per day you can use it to strike with the blessing of Thor and add 1d4 to your d20 roll." Nothing game-changing, just enough to let the player know that their god is real and watching them. Eventually they'll find a magic weapon and stop using the blessed warhammer, and the blessing won't pass with the hammer to anyone else, so it's more about the gesture of favor than any lasting upgrade for the character.
Involve the gods in ways that make the cleric more important to the party. A divine messenger gives the cleric a special item to use for a quest the party is undertaking. A raven brings a dried ear of corn to the cleric, and the ear has three kernels remaining. During the quest, once per day the cleric can commune with their god using the ear, and a raven will come. After feeding the raven a kernel, the raven will answer one yes/no question and then depart.
I'm surprised your group values bards over clerics. In the games I play in we almost always have a cleric but bards are among the least-chosen class.
