I get what you are saying,
however a couple of points to note.
if you spend 120k on a sports car, you will expect it to depreciate by 50% even if it is a petrol version.
batteries are massively expensive and would cost a fortune if you had to replace it.
the comparison is, if you need to buy a new engine for a car, expect to pay in the region of half the original car purchase price.
i.e. my last pickup truck cost 24k and a new engine costs 11k, expect the engine to break down after 200k miles even if well serviced.
when it breaks down you don't run to the nissan dealer and say "put a new engine in please" generally speaking, they change the part that has failed,
and in serous cases a rebuilt or second hand engine is sourced for 2k to 5k
with an electric car, you are in a similar position, you can if you wish say to the dealer, put me a new battery in please and they will bill you 10k to 15k. or you ask for it to be fixed or replaced with a refurb unit.
they are modular, containing multiple modules that contain multiple battery cells.
they can diagnose the modules that have failed and replace them individually,
or in the worst case they can change the battery for a reconditioned unit, depending on the condition of the battery you are giving them, the costs range from 30% to 60% of the new battery cost. 4.5k to 9k (working on the 15k replacement cost)
I was not a believer in electric cars a few years ago and kind of smirked a little when other family members got them and sang there praises.
they are absolutely NOT RIGHT FOR EVERYONE.
however, for me over the next 10 years i expect to save
£7300 x 10 =73k in fuel
£250 x 10 =2.5k servicing
£300 x 10 = 3k road tax (although they may well reduce that incentive)
£30 x 520 =15.6k emissions charges for driving into birmingham, sheffield and bristol. (based on 2 x per week average)
£94k savings over 10 years buys a lot of spare batteries if i ever need one.
but to top it off, it is the most fun car I have ever driven and will do 0 to 60 in 4.2 seconds and that on occasions brings a smile to my face!!!!