The Leaf's battery problems are not down to the chemistry - they're fine. Even the old packs weren't bad at all, especially considering AESC was the only car manufacturer even trying to use LMO. All of the battery woes are down to not having any thermal management.
Lithium ion batteries have performance and degradation characteristics that vary WILDLY with temperature. In the Leaf 40's battery pack, it is common under almost all circumstances for the rear module stack to be easily 10 degrees C (about 20F) warmer than the frontmost stack. That by itself means the rear stack will degrade about twice as fast (on long timescales) but also that it has lower internal resistance, i.e. higher current load during both discharging and charging which also increases effective cycle load.
But probably most importantly, without a way to heat up the battery, under everything but short sleeves weather, the battery is routinely damagingly loaded. You can't expect a pack at near freezing to happily discharge at 3C (300+ amps) to accelerate, nor to accept regen braking as often and harshly as it does.
Then, when the battery has heated up, it has no way to cool down. If you fast charge at all, the battery jumps to 45C and stays hot for at least half a day after use. Batteries are actually fine being hot, consider Tesla's batteries which are actively heated up to accept a fast charge. The difference: they get cooled down to ambient as soon as you exit the car, keeping them hot and degrading for as short a time span as possible. Keep the battery hot for basically half the year and you've got a battery that degrades 4-8X as fast just because of Arrhenius' law.
Oh and the 40/62 share chemistry with the 30! And the BMS as well. If you want to know how the cars/batteries last, look at historical 30kWh data and make it slightly worse for the 40 (due to higher thermal load) and slightly better for the 62 (due to higher battery mass and lower RMS C-rate, causing less heating on typical trips).
On GMs batteries: It shows that even commonly derided LG E-type cells (as also used by EVBR) CAN be used and CAN last a long time without sacrificing system energy density too much. Again, the secret sauce is just an adequate BMS and some fairly aggressive power throttling when the car is threatening to exceed the datasheet performance. I think that's the ultimate dirty secret of batteries: they can be as crap as you like, if you manage them well they'll last forever.
Tesla doesn't necessarily have good drivetrain performance, they just have slightly more aerodynamic cars. Tesla's system efficiency is actually quite bad all things considered, but that has more to do with their excessive idle consumption and battery TMS overhead than their powertrain. The Ioniq is definitely in another class of car if efficiency is concerned; with no idle consumption and surprisingly little TMS overhead despite having decent battery life. Then again, the Ioniq seems to degrade about twice as fast as the Model 3 batteries, so is the overhead worth it? Probably! Again, I try to convey as much as possible that Tesla's batteries/cars/etc. aren't magic and aren't actually particularly good on any individual aspect (there are better examples all around) - they just have a really well-balanced package and know where to focus to give the best customer experience of the car. That's what makes a Tesla such a great car to recommend. You're not going to be disappointed, the best you can do is have differences of taste in certain design decisions.