The schemes mentioned in articles like this are almost exclusively targeted at brand marketers. My guess is the problem lies in the way that large brands incentivize the people running their campaigns, because the technology exists to knock out the vast majority of this type of fraud. Companies like Coke hire ad firms that send them reports about impressions, and they are thus incentivized to not pay attention to traffic quality, and just maximize impressions. That has to be the problem, because just my internal traffic quality tools that I have written would have shutdown ad delivery on the sites sending such obviously bad traffic within a few clicks from each referrer - and I don't claim to have written the most sophisticated filter out there. There are many ways to do reality checks on traffic, on a per-referrer basis, and cut out much of this stuff. Webview traffic (the kind being taken advantage of here) is among the easiest to detect.
As to your question about measuring ROAS it's simple for performance marketers. Take your ad spend and compare it to revenue. I'm not sure that brand marketers have a reasonable way of determining ROAS, either online or in the physical world. I suppose they could take brand recognition surveys and compare before/after a given campaign, but that is hardly an exact science.