Well this would be good news if there were no other studies on diet drinks.
Ben Johnson

Generally speaking, all of the associations you mention disappear when, as with this study, the researchers control for things such as socio-economic status and obesity.

The fantastic Scibabe has written a very lengthy refutation of all the points you’ve mentioned above, which is far better than I could do and I recommend you read https://theoutline.com/post/842/diet-coke-is-not-killing-you just replace “diet coke” with “all diet drinks” because the research is largely the same across diet drinks.