Costs have actually been increasing in recent years for critical components due to higher energy costs, which leads to higher freight costs, higher labor costs, etc. Demand/competition for components has also increased due to AI buildouts.
Apple does a really good job of leveraging volume of sales to secure best-possible pricing, which then feeds into a lower overall price customers pay.
Elsewhere, you see Samsung reguarly bumping their prices by $50-$100, and now Google too with the latest Pixel devices. Apple deserves a lot of credit for keeping prices lower.