You get direct access to AppleCare+ , which typically offers better repair quality and faster turnaround than carrier insurance.

Carriers like Verizon and AT&T are the strongest choice for high-value promotions.

Retailers like Best Buy and Walmart offer a middle ground with frequent sales and specific perks. iPhone - Buying iPhone - Apple

Most iPhones purchased from Apple (except for those with specific AT&T installment plans) are unlocked, allowing you to switch carriers at any time or use international SIMs while traveling.