We do have good statistics. Battery health reporting firm Recurrent found that of all EVs sold to date, only 1.5% have received battery replacements.  Here are the numbers for popular EVs:

Tesla Model S   3.75%  (for all model years; Model S has switched battery chemistry and improved cooling, which has since led to improved reliability)
Tesla Model Y   0.29%
Tesla Model 3   0.34%
Audi e-tron   0.41%
Tesla Model X   0.79%
Chevy Volt   0.95%
Jaguar I-PACE   1.32%
Nissan Leaf   4.92% 

AutoTrader did a story (available on YouTube) about a Tesla Model S with original battery and motor with over 430,000 miles that only lost 13% of capacity after 10 years.  It is owned by a private taxicab driver who says he Supercharges it 95% of the time.
 

There is data on how many batteries are being replaced during the warranty period for Teslas. It was provided on other NBC articles on this topic. The number was very low.
But one also has to take into account the calendar life of a lithium battery. There are batteries that boast a 20 year projected lifespan (some new chemistries from Chinese manufactures). But most lithium batteries have a 10 year shelf life.
Basically at some point we might find 10 year old Teslas with low mileage. Those will look good. Won't have body rust due to aluminum. But their batteries will give out the ghost simply from age. And there certainly will not be 'classical' drive-able Teslas on original batteries after 30 years.

Uhm, that's not how statistics works.

You can't take a few selected examples and generalise to the entire population.

There are all sorts of sampling biases in this. For one, all the samples are people trying to prove, or were surprised to find that in their case, EV batteries are reliable. They're also EV early adopters (by definition), and so have a stronger motivation to report success.

Also, we have no data on failures, people whose EV batteries died unexpectedly quickly.

A meaningful analysis would be to get data from a wider set of randomly selected owners (preferably > 1,000) across multiple makers for a period of a few years and see what the longevity rates look like across the board.