The solar roof and storage battery is part of the greater plan with Tesla products. The up front cost is still huge.
I live in a rural area where ride sharing is not realistic (although until quite recently lived in the heart of Silicon Valley for many years, which will probably be on the forefront of this change for obvious reasons).
There will also be weather to contend with (snow, etc), and other obstacles. Perhaps the biggest one being the large distance between properties/the destination, increased wait times or more unpredictable arrival, and reduced overall demand due to a lower population concentration.
One more thing to consider is what will people do with all those combustion engine cars? Will someone (possibly low on funds, maybe saved for years for their car(s)) just stop using $40K worth of vehicles parked in their garage? Or will they run them into the ground for the next 10 years before upgrading to shared rides or their own automated electric vehicle (by then probably better and cheaper).
It will be interesting to see how the technology fares outside the city, and how long it will take to reach these areas. Most definitely more than 2 years.