The Lost starts with fairly abysmal values and so if you don’t get good enough items in that first floor, you’re going to struggle as you climb further down towards the depths. It’s an item that you can, if the RNG gods favour you, pick up in a run but the Greed Machine guarantees it every time.
You can, by means of donating 879 coins to the Greed Machine, start with Holy Mantle, an item that allows you to take just one hit in each room. This means that they are eternally stranded in one-hit mode. They start with no health and cannot pick up any soul hearts or upgrades.
None are more bewilderingly underpowered as The Lost. In The Binding of Isaac, you can unlock a whole roster of characters with their own starting stats, items and hindrances.