well, perks make campaing easier but you are free to not use any perk
in fact, we could also add perks that makes campaing even harder, while also increasing reward you get
"Castitas": whenever you destroy building or kill an enemy before taking all loot boxes you take damage 25% of max HP. Damage can only be avoided by taking all of loot boxes first. In boss stage, you are allowed to beat boss first (and take 25% damage) before taking loot and engaging other enemies.
"Temperantia": boost crates on the map are replaced with loot buildings, giving you no boost. Boss missions included.
"Caritas": in battles, your enemies start first and have 3 actions in their first turn (because you gifted your first action to them)
"Industria": cannot deactivate drone or shield or shut engine down manually, cannot move if you can fire at least one weapon.
"Patientia": cannot use teleport, harpoon or charge, your legs' max movement is reduced by 1
"Humanitas": your weapons deal as much damage as their explosive equivalents (read: less than physical weapons), but deal no heat or energy damage. None of 3 damage types have their advantages here.
"Humilitas": each tile with loot is replaced with extra enemy. 1 loot crate is a tank, 2 is a mech, 3 is a heavy mech (+40% hp, +20% heat/cooling/energy/regen, same damage). You still get same loot crates after you defeat these enemies, along with exp/gold reward for enemies. In boss mission, defeating the boss provides you with additional 2 standart issue 50% repair boosts before you go after those new enemies.
All challenges also forbid using revive
Best variation would be "Virtue" perk providing random of 7 challenges each time or letting player to choose one of 2-3 random ones, meaning you cannot prepare for specific challenge (by, for example, unequipping teleport, harpoon and charge and taking weapons with better ranges, before engaging Patientia). Other option would be each level recording all challenges-"assisted" wins against it (and probably giving an extra reward if you beat it with every one challenge)