GOOGLE AI says:

The saying "a shoe in heaven is worth a foot in hell" highlights the value of a small piece of good fortune over the suffering of a difficult or unpleasant experience. It implies that even a minor positive thing can be more desirable than enduring severe hardship.

In simpler terms, it suggests that a small blessing is better than a major problem. It's a way of comparing the relative value of two options, one offering a small positive and the other a large negative.