Half a year ago, in Bug 41125, $wgMaxImageArea and $wgMaxAnimatedGifArea were raised to 25 MP, and there have been no adverse effects. We are likely only talking about a few thousand images remaining that are above that limit, but it continues to be a problem for special areas like complex animations and archival-quality scans, some of which are features images on projects. And this will only become more common with time. I think the raise from 12.5 to 25 was relatively conservative given modern technology. A normal quality archival scan from even 5 years ago was already commonly producing images of 40 MP or more depending on the size of the document (we just don't have many TIFFs in general, so it hasn't seemed like a common problem).
I am wondering if the fact that there are so few of them means we could still render nearly all of the ones on Commons without a problem. Could we just set the arbitrary limit to something very much higher, like 100 or 200, just so no one can do anything too malicious?