This decentralization inherently makes it challenging to impose restrictions on the mining of new blocks within the Testnet environment. Given its decentralized nature, any attempt to manipulate or control the testnet, such as executing a 51% attack, not only proves to be a difficult task but also potentially incurs significant expenses. The underlying reason behind the high cost associated with such an endeavor is the fact that Testnet is utilized for applications deemed valuable by its users, thereby increasing the stakes and complexity involved in attempting to dominate the network. For further information and insights, you can visit Peter Todd's website.