I generally keep a car for 8-10 years and am ready for another and am worried that parts and service will fall off as Volvo moves to all electric.

How worried should I be?

 

Less than with a gas powered car! Electric cars are actually more reliable than gas cars - no complex ignition/emissions systems, simpler transmissions etc. Data is already showing the maintenance costs for electric cars is way lower than gas. Most common maintenance area is going to be software updates. The only point of concern about electric cars battery life and whether its reasonable to assume the battery packs can last 10 -20 years without needing replacing. Here, the technology is getting better each year so when your e-car is 10 years old, replacing the battery packs will be "better than new" (ie longer range, faster charge times etc).

 

I think the OP's question was wondering if future electric cars/availability will impact the value of a "new today" IC car. Probably more a political than engineering question - how long will subsidies last? Will fuel be taxed into oblivion? etc. etc.

"Here, the technology is getting better each year so when your e-car is 10 years old, replacing the battery packs will be "better than new" (ie longer range, faster charge times etc)."

Moore's Law is not going to work here - the energy available per unit mass is determined by atomic parameters in the Periodic Table - no amendments, adjustments or revisions allowed. Thus, aside from modest improvements in packaging, the size of an XX kilowatt battery will be the same 10 years from now. Charging times may be shortened but again it's all about energy transfer - a system that would charge a Tesla battery in 5 minutes would require cables the size of a garden hose or larger and carrying enough current to cause an explosion if the two conductors are shorted.