They are right at their core though and it would be good to question, if we need high definition screens and streams all the time everywhere. It's not only the environment, it is also often detrimental to the device and user themselves. Look at e-readers to see what kind of devices we good have for special purposes if not every consumer computer needed to be a media powerhouse.
And then we need to go further and ask ourselves, how would it benefit the environment if we had stricter rules for unnecessary data transfers in general. Because I would think, cutting down on adware and excessive file sizes on the top 10% websites would give us significant savings on bandwidth, emissions and lets be honest, improve UX quite a bit for most people, especially on slower devices/connections.
And of course, the article points out, that while these things are important and can help, the are dwarfed by other factors that really need to be tackled. No reason to ignore the smaller stuff, though.