Surely that depends on your usage/charging and when you do the reading. It's not unknown for cars to show 100% full then drop more than expected after a few minutes of usage.
How many miles have you on the car? Studies on usage have shown you lose about a bar on the battery every 12K miles after the first 16K miles. As you've 8K miles a year thats 40K miles so I'd expect your battery to be 75-80% after 5 years use.
https://www.nimblefins.co.uk/nissan-leaf-battery-capacity-range
My 20 year old car allegedly left the factory with 350bhp but always measured 343-346bhp, until I had some work done, where it was 380bhp
Cars don't lose a huge amount of power over years now.
My car has 22k on the clock, bought at 18k 3 years old in October. Battery condition went up from 94% on purchase to 95%, probably due to minor self adjustment and the increased number of cell balancing opportunities when I do my deep discharge daily commute.
The link you provided is fishy. Only sampled across 500 cars, 2011-2015-ish Leaf in America are known to have battery degradation in hot weather. 2013-2017 Sunderland built Leaf 24 and 30 are much more robust. This 2013 built Leaf with 100k miles on the clock in 2015 still has full battery bars:
https://www.zap-map.com/electric-taxi-company-clocks-100000-miles-in-nissan-leaf/
I admire your optimism, but id love to see some real data, not just what you expect. My experience of higher power rechargeable batteries is woeful when they have some use on them , they also tend to die very quickly! Also when they are subjected to cold temperatures capacity just vanishes.
You are talking about a £70k+ car with a Tesla and you can buy a whole lot of power and performance for £70k. If im spending £70k it wont be on a Tesla or indeed any EV!
EV battery are hardly the same as high power rechargeable batteries. When you leave your EV plugged in, it doesn't trickle charge the car at 100% like your laptop/phone. My experience with high powered Li-Po drone batteries tells me they are excellent as long as not left sitting at extremes (0 or 100% charged), I've had my drone for 3 years now and still get the same amount of flight time as before.
The cold temperature issue is true with my Leaf, 20% reduction in range compared to 10% reduction in MPG for ICE cars. Not too dissimilar. Similarly, I had to queue 1 hour to get out of a town last Friday in the snow, nudging forward slowly, a total distance of 1.2 miles. My fuel economy was in single digits. But in an EV, I would have only used 3kWh to keep the heater on, zero power is wasted moving forward slowly.
If I were to be spend £50k+ on a car, it will definitely be a Tesla Model S, No question about it. The EV powertrain driving experience is just so much better than ICE powered cars. As mentioned previously, Tesla supercharger infrastructure provides long range travel so there's no longer any real advantage to ICE cars.
For anything with a sensible amount of power, the answer is "slip roads joining a motorway is pretty much it" but even then the legal limit arrives very fast. On my car (not a TVR) that's just before the 7300 rev limiter in second. At least it sounds nice as the engine winds up in second gear while it gets there though
Driving an EV lets you enjoy great acceleration from stand still up to 30 mph
Higher power EV such as a Tesla gives you fantastic sense of power all the way to legal speed limits.
The sense of immediate power is very addictive. No turbo lag, no unpredictable kick-down power surge, no wait for slush-box to shift mid-roundabout. Just press the go-peddle and you always get exact amount of power you demand.
Cars aren't just transport, they can be very emotive. Even those that say they aren't still pick a colour
But the emotional attachment to ICE is going to go the same way as preferring to tend to a horse for your transport needs. The attachment to a brand that has "sporting pedigree" just seems plain stupid to me. If a new brand makes a superior product, then why dismiss it? I honestly don't see ANY reason to choose Jag I-Pace over a Tesla. The former doesn't have the charging infrastructure, no OTA updating firmware, and still sells their cars using slimy dealers.