Please note this is an ieee.org article, targeted at electrical/electronic engineers, talking, in part, about peer reviewed research [1], which you're calling napkin math. There's lots of money and focus going into lithium-sulphur batteries, because they are promising, and any engineer that works with batteries is keeping an eye on them.
Talking about the possible future, and shortfalls of the current state, isn't useless, it's the foundation of engineering. And, it's fun.
It's "IEEE Access".[1] That's the low end of IEEE publications. Costs US $1,995 to publish an article. There's some minimal peer review, plus they run the content through a plagiarism checking program. This is two notches down from Proceedings of the IEEE.
Sure, but calling it "napkin math" is disingenuous. If there's a specific problem with the math presented, they should point it out, rather than slandering the authors.
Every time something is defended like this, it's usually bullshit. There's just something about appealing to the authority of the thing and being outraged that one would consider that authority nonsense. Most often happens to bullshit. Usually accompanied with adjectives "problematic", "disingenuous", or "no evidence that". Strong markers of nonsense.
Talking about the possible future, and shortfalls of the current state, isn't useless, it's the foundation of engineering. And, it's fun.
[1] https://ieeexplore.ieee.org/document/10418456