Battery chemistries have changed and technology has improved a lot in that time frame. Those 15 year old Nissan Leafs have terrible battery degradation, because they're not liquid cooled (hot = bad) and used batteries that degrade fast (LMO, which autocorrect thinks should be spelled LMAO). Manufacturers learned their lesson and every EV built in the last 5 years is far better on both counts.
The only thing you can fault them for is for how long it took to switch to liquid cooled.
The leafs are fine cars but you're paying for being an early adopter. I bought one used in 2016, used it as a daily commuter till 2025 and then sold it. I don't think any car will ever be as cheap to run as that one....