I just checked the source code, yet again. Indeed, there is a BackendUri variable pointing to "https://api.wasabiwallet.io/" by default: https://github.com/WalletWasabi/WalletWasabi/blob/e8a6e55737b554276948a403aab2fb070b3fe671/WalletWasabi/Helpers/Constants.cs#L12.

This means that if wasabiwallet.io is ever taken down, everybody's client software will need to update, with another backend. And until that new API server is created, distributed and updated in a new version of the client, Wasabi users cannot access their wallets. Why is this designed so centralized?