I don't know what expectations these are defying unless they're from those created by anti-EV FUD. I thought it was pretty clear that EV batteries usually last longer than the cars themselves.
Then you haven't been paying attention.
If 250K is exceeding expectations, then the expectations are wrong and haven't been supported by the data for a long time.
The problem is we haven't had data for a long time. You only need to go back a decade to find several year old early Leafs demonstrate poor battery performance. Yes around that time Teslas were starting to show people and the industry that batteries do last a long time, but that was initially an outlier in an industry that notoriously had no fucking idea what it was doing.
Cars universally having proper battery management really are post 2015 thing, and you need to add 5 years for data gathering, and THEN we can talk about perception changes. Yeah even today there are many people who believe EVs are battery life limited because only 5 years ago they would have been able to find data backing up that belief.
One of the problems is cars in general. People view them as a slow moving technological turtle. In reality the EV space is a technical marvel where even today the battery design deviates greatly from that of only a few years ago with wildly different approaches to how the manage battery packs. As such their perceptions are based on ideas that are usually well outdated (fun fact: ask someone what is more fuel efficient, leaving a petrol car in gear or putting it in neutral when coasting down hill, I bet they'll give you an answer from the 80s (put in neutral) rather than the answer which has been correct for every car manufactured in the past 20 years.)
Add to that general incompetence. (Fun fact: The 2023 Opel Corsa *STILL* didn't have 12V battery management systems in place. And right until mid-2025 Teslas *STILL* suffered dramatic vampire drain on their primary pack. And even to this day many cars including the Mustang *STILL* doesn't pre-condition the battery pack in cold weather with cabin preheat leading to shitty range). We're in a world of people who have no fucking idea what we're doing.