Depends on how you build a cleric, but they can easily be frontline or backline. BG3 started us off with the weirder end of Clerics by giving us a low STR/high DEX Cleric that is meant to be more backline, while most people I feel tend to build a cleric as a Melee Weapon and Shield type.
Because the cleric has a lot of 'melee' spells and if you want to use them on companions, then you need to come close. I would like to play a distant cleric, but then he just turns into an archer... I'm talking about those spells that don't need a spell slot. Maybe it will be different at higher levels, but right now it feels like this.