There isn't really a reason to expect a significant effect, in practice, Tesla COGS/unit plateaued a few 100K ago. It's a bit too abstract and high-level.

Batteries specifically does make sense, ex. Model X has 100 kWh battery. if I price out 100 kWh at $200 right now (high) and its $100 a decade from now, about $20K.

"Software" is hand-waving.

Electric motors being easier does make sense.