The Supercharger network is one of their remaining competitive advantages. Other manufacturers were behind for years on efficiency, range, etc. but are now catching up - and other manufacturers are far better at making an actual _car_ than Tesla. Build quality, quality control, durability, comfort, noise, etc.
Unless Tesla is so confident that their manufacturing skills will give them a continuing and durable cost advantage - that makes up for the fact that they haven't innovated or even improved their basic vehicle design for the past 10 years - I don't see how this works to their advantage.