I do agree that Tesla isn't investing that heavily in R&D but they also cannot afford to. They are not turning profits. And they are already 5-10 years ahead of many competitors on tech, so I think it's wise to invest in production capacity instead. This year and in 2021, VW, GM, Mercedes, BMW etc. are getting into the EV market with cars that in specs seem to be competing with Tesla's 2012 model S.
The most important spec right now is price and range. None of the old companies are close to delivering competing range at a competing price. None of them have a charging network or battery efficiency or battery production capacity close to what Tesla has.