The single USB-C port on the E series remains the only charging port last time I checked, so you can't use it and a charger at the same time.

Lenovo lettering denotes build quality. By definition an X series will outlast an E series in longevity of the physical device.
I speak from experience as well, as I support a Lenovo based business. Our T420/430/520s way outlast the E530/531/540s wrt the chassis, lid, and especially hinges.
8GB of RAM is plenty.

"Aside from the budget-oriented ThinkPad E series, ThinkPad laptops are some of the best that Lenovo has to offer in terms of serviceability and longevity."

Compared to the Carbon X1 the E series from the same year came with Storage and RAM that is fully user upgradable (two RAM slots for dual channel configuration, one PCIe M.2 and one SATA slot), also it was available with core i5 and even i7 CPUs with more horsepower than the mentioned Carbon X1 and in addition to that it was also available with a black alloy chassis top shell which makes the device more durable than average plastic Laptop Chassis.

Please explain, what exactly the Carbon X1 has more "to offer in terms of serviceability and longevity" than the E series you set "aside" in the very first sentence!

In case you don't know about the real differences:
The Carbon X1 has thunderbolt in the USB C formfactor whereas the E series only got USB C but it still support full connectivity to the ThinkPad Dock with up to two additional screens, ethernet, power delivery and of course many more usb ports.
Ports differ between the E series and the Carbon X1– the latter has less. I am not sure if the X1 has a ethernet port or if you require an adapter or dongle or even a well above $100 dock to connect it via wire to a network.
And the final difference is the weight: the Carbon x1 spares a few hundred grams (I guess... It is definitely lighter but I can't remember to what extent).

So in conclusion it's fair to say that if you don't care about a little more in weight to handle (and remember, we are talking about maybe 300 gramms or so, nothing too much!) the E series comes with the option for fully upgrading RAM (no RAM is soldered here; two slots available!) and Storage devices (you can also use a M.2 NVMe drive PARALLEL to a 2,5" SATA drive) but the BIG advantage of the E series are the many ports, so you don't necessarily need any dongle to use all the connectivity, if you're willing to waive thunderbolt. But as the USB C port on the E series is very happy to deliver power, ethernet, two additional displays and many USB devices all at the same time, I cannot imagine a reason to necessarily need to go with thunderbolt in this scenario.

The author of this "article" did either a poor job of research or a poor job in writing this. Maybe both.
There are good reasons to prefer the E series ThinkPad with the 8. Generation of Intel core processors over the Carbon X1 as I explained. But there is also a criterion which made the the X1 the better choice. Unfortunately non of these were mentioned in the announcement.
:(

Who would want a pc with 8GB of memory?  Cannot be upgraded; it's soldered.  Worthless.