Glad to hear that Nissan Leaf battery life is much better than all the reports I've read. Must be FUD! So Tesla are waisting our money incorporating battery conditioning systems? I note that Nissan have introduced some form of conditioning on the latest Leaf.
Nissan starts new program to replace old LEAF battery packs - Electrek
I always liked the Leaf, but reported battery life was one of the things that put me off. Of course, Tesla's have to survive the extreme temperatures in Death Valley and Norway - not a problem in UK.
Not sure about Tesla taking a bath on PW2. They keep putting the prices up! But I agree, competition is good.
You need to do a bit more research to understand this issue, but I'll try to give you a summary.
Basically Nissan packs are fine when they are used regularly and not too heavily. So the taxi example is kind of the best case - mostly low speed around town, some sitting around waiting etc, and some rapid charges that warm them up but not too much.
People who do see more degradation tend to have older, relatively low mileage cars, that have been sitting around at high SoC for long periods.
The issue with the 30kWh packs was mostly due to a software bug that reported the SoH incorrectly. Nissan did an update to fix it and it appears to have worked. They also offer replacement packs although I don't think many have been sold, in fact I'm not aware of any in the UK. The car tends to reach EoL before the pack does.
Obviously active thermal management is a good idea for cars. I'm somewhat skeptical about Nissan's 62kWh packs because they lack it. For smaller packs they can get away with it, but the 40kWh was borderline and even with the software fix doesn't work all that well (lifetime TBD, it's too early to tell).
But home battery packs are a different kettle of fish.
They get cycled every day. Charging is relatively slow, discharge is relatively slow. Being indoors the ambient temperature is at least somewhat regulated. The BMS is free to limit charge and discharge as necessary.
Tesla are having problems getting their battery costs down at the moment, which is why they are taking a bath on them. For example, they really really don't want you to buy the base Model 3 because even with all the other downgrades the battery is still too expensive and they lose money on it. Panasonic has given up investing in the gigafactory and developing the battery tech because Tesla doesn't pay them enough already, i.e. they can't make any money.
The main issue they have is that they picked the wrong technology. They are making cylindrical cells, which are high reliability and can charge/discharge at high rates but also cost more. Other suppliers have mostly gone to pouch cells, the kind you find in mobile phones. They cost less to make and although you can't charge/discharge them as hard it's more than adequate for most cars.
In fact the cost is so much lower that pack manufacturers use simpler BMS and conditioning systems, and instead over-provision the packs more. So actually when you look at a BYD pack that says 14kWh usable, when new it will actually offer significantly more than that. People have found the same thing with cars, e.g. a "64kWh usable" Kona will offer over 66kWh usable when new.
In summary you have to be careful when comparing batteries from different manufacturers. The capacity rating is a nominal number and the kind of conditioning system in use doesn't really tell you much about reliability or expected lifespan.