Those images found on the pages you mentioned are really small, "optimizing" them will save only very few kilobytes at most, thus in total the size decrease for the whole page still falls under 100 KB. The page that is worth optimizing here is Far lands, full of high-resolution screenshots.
On the other hand, you can count the number of pages with many images on this wiki, including ones with small images like Spawn egg, and divide the number by total pages, I believe the result will be under 2%, or eventually 1%.
(In response to Nixiova...)
Those images found on the pages you mentioned are really small, "optimizing" them will save only very few kilobytes at most, thus in total the size decrease for the whole page still falls under 100 KB. The page that is worth optimizing here is Far lands, full of high-resolution screenshots.
On the other hand, you can count the number of pages with many images on this wiki, including ones with small images like Spawn egg, and divide the number by total pages, I believe the result will be under 2%, or eventually 1%.