The LEAF batteries are air-cooled (not particularly well, especially as compared to liquid cooled batteries that most other pure EVs use). They’re also relatively small, meaning typical use will cycle them deeper than a car with 3x the range.

As a result, they lose capacity far faster than other mainstream EVs.

I’m a 2015 LEAF owner for almost exactly 9 years. In that time and only 25K miles, I’ve lost a little over 15% of the battery capacity. A Tesla would have lost about 2-3% over similar service. (I also feel the loss quite a bit more, starting with a range that was optimistically estimated at 85-90 miles when brand new.) The 2015 packs were supposed to be better than the older gen batteries (and probably are), but it’s still a pretty poor design if longevity and range retention is your priority.

I also had the pack disassembled and a module changed under warranty after it degraded much faster than the sibling modules.

Despite all that, I do enjoy most aspects of the car; we live in a city and have plenty of very short-range trips where the car is quite nicely matched and pleasant to use.