Length is the record that seems the most untouchable at the moment. Three of history's five longest coasters are defunct and have been demolished today. Only two coasters longer than 2000 meters have been built after the year 2000, out of 9 coasters total. That new Guardians of the Galaxy coaster at Epcot is the third longest coaster built in the world since 2006 (not counting Steel Vengeance, whose length is largely a consequence of following Mean Streak's old layout). Most of the longest coasters out there are good ol' Hypercoasters and Giga coasters, but even when those are built nowadays, they tend to be on the shorter side compared to historical ones like Fujiyama or Desperado. Even Orion at King's Island, which is only a smidge shorter than Steel Dragon 2000 height-wise, is only two-thirds its length. It's actually much shorter than Gao at Greenland, which is less than half Orion's height. I guess it has to do with cost of materials. A shorter coaster is just cheaper to manufacture and set up, which makes going for the length record very expensive and thus unappealing.
That being said, Formula Rossa came quite close to taking the length record, unofficially clocking in at 2120-2150 meters according to
this thread, which makes it the third longest coaster currently in operation, and the fifth- or sixth-longest ever (it'd have to reach the upper limit of that interval to surpass Son of Beast). If anybody were to commission a similar coaster to break the speed record, maybe the length record would also be claimed at the same time.
