What's wrong with -greedy?

Throughout the book, we have used the -greedy exploration strategy as a simple, but still acceptable, approach to exploring the environment. The underlying idea behind -greedy is to take a random action with the probability of ; otherwise, (with probability) we act greedily. By varying the hyperparameter, we can change the exploration ratio. This approach was used in most of the value-based methods described in the book.

Quite a similar idea was used in policy-based methods, when our network returns the probability distribution over actions to take. To prevent the network from becoming too certain about actions (by returning a probability of 1 for a specific action and 0 for others), we added the entropy loss, which is just the entropy of the probability distribution multiplied by some hyperparameter. In the early stages of the training, this entropy loss pushes our network toward taking random actions (by regularizing the probability distribution...