The core of Bitcoin's system revolves around Unspent Transaction Outputs (UTXOs) rather than conventional account balances. Addresses, which many users interact with through wallets and blockchain explorers, do not hold balances in the protocol's view. Instead, these tools calculate an address's balance by summing the values of UTXOs that can be spent by the address in question. This method is fundamentally different from how most people perceive transaction processes, underscoring a local interpretation rather than a protocol-level operation.

The proposal to credit an address directly, aiming to streamline or improve upon the current process, faces substantial technical challenges due to the foundational design of Bitcoin. Such changes would necessitate a complete overhaul of the protocol. Moreover, introducing a system that differentiates between primary recipients and change addresses could potentially undermine the privacy benefits inherent in the UTXO model. In Bitcoin's current design, it's often not possible to distinguish which outputs are payments to recipients versus change being returned. This obscurity is intentional, providing a layer of privacy for transactions.

Adapting Bitcoin to a direct balance model—where transactions simply adjust the balances of addresses—would drastically alter its operational and privacy characteristics. While it might address certain issues like coin selection, dust accumulation, and the growth of the UTXO set, it introduces new problems, notably in the area of privacy. A balance-based system would likely discourage the use of multiple addresses due to the associated on-chain costs, leading users to consolidate funds into fewer addresses and thus reducing privacy. The current model, despite its complexities, offers significant privacy advantages by making economic sense to send change to a new address without additional cost, unlike a system where each address adjustment incurs a cost.

In summary, while proposals for altering Bitcoin's transaction model aim to address perceived inefficiencies or limitations, they must contend with the fundamental principles and trade-offs embedded in the protocol. The balance between privacy, efficiency, and flexibility has guided Bitcoin's design choices, with the UTXO model serving as a cornerstone of its approach to decentralized digital currency. Any significant modifications would require widespread consensus within the Bitcoin community and entail a careful reconsideration of what users value most about the platform.