I respectfully disagree.
I've been in the electronics manufacturing industry for most of my life. The expected lifetime of an electronic/electromechanical product is often defined by the "bathtub curve", as shown below...
Bathtub curve - Wikipedia
Units that fail upon initial power up (and shortly after) are victims of "infant mortality", as time moves forward, there are fewer and fewer infant mortality failures. As time progresses the device operates in a time frame where random failure seldom occurs. In most cases this interval is measured in years. After that long interval, more failures start happening. This happens at the end of life for the product. The products wear out.This applies to the product itself, and to each and every resistor, capacitor, active electronic device, motor, sensor, nut, screw, solder connection, everything that makes the product work. While DJI may not do accelerated lifetime testing of their product, the manufacturers of the components and sub assemblies probably do. It's sometimes referred to as HALT testing:
Highly accelerated life test - Wikipedia
If a product works properly for just long enough to have it move past the interval of infant mortality, the product should work fine for it's expected service lifetime. A responsible manufacturer will warranty their product to cover the interval of infant mortality, and slightly beyond it.
The bathtub curve nicely explains why an extended warranty is a cash-cow for the manufacturer of the product. There is real science behind it. Cheers