Re: "the Morefine M700S isn't a great deal overall. " ... indeed
They were comparing the model of the computer with the same model, made by the same manufacturer, but with an Intel chip. That's why they were using a 2023 Celeron instead of a 2020 I3 as a comparison. I'm not them, but I can answer some of your questions.
"The story claimed i3-10000 series compute, not Celeron.": I've explained why they did that. From benchmarks, the N100 is a little slower than the I3-10100, though much more power efficient.
"A quick research shows 16gb of DDR4 and 256gb of SSD are both $50 [...] I don't see how even a new Celeron will be $130"
I couldn't find the specific model they were looking for, but those prices do exist. I found one from the same company with an N100, 12 GB of RAM, and 512 GB SSD for $144.06. The RAM is a bit lower, but the larger disk probably offsets that. From a different provider, I can match exactly, $129.98, 16 GB RAM, 256 GB SSD. These are from AliExpress. Add $20 and I can get you the same thing on Amazon (US Amazon so I can keep quoting USD), but it's Amazon, so if I search for twenty minutes instead of twenty seconds, I might be able to match it without the premium. So yes, you can get that spec for that price. I wouldn't want to count too much on that warranty.
"a perusal of Newegg shows i3-10000 series desktops going for -$440"
That may be, but there probably aren't many and they're probably not selling. The processor being old enough means that people can easily get a better box for the same price or a comparable one for cheaper. I can easily double the performance for that price.