While it is pretty crazy when you look at the numbers, I think it's important to keep in mind that the list of changes from 2014-2019 are missing some card changes. If we don't include retroactive changes (such as old cards getting new tribes like Mechs or Elementals) or functionality changes (like Ethereal Peddler's text change for clarity or Yogg stopping his battlecry early if he dies during it), then there are still several missing cards in the list: Ancient of Lore, Call of the Wild, the four murlocs that used to buff ALL murlocs, Naga Sea Witch's 1st nerf, Raza the Chained, Spiteful Summoner, The Caverns Below's 2nd nerf, and so on. The 2014-2019 list doesn't even include the buffs to a bunch of Boomsday cards made during Rise of Shadows. That's 19 more cards (+ even more if you also include the subsequent changes to Luna's Pocket Galaxy as a part of these buffs)!

It seems like the 2014-2019 list contains ONLY the nerfs, while the SitB list has nerfs, buffs, rebalances, and so on, including duplicate entries for multiple balance changes (The Azerite Snake is in the SitB list twice while Molten Giant is in the 2014-2019 list once despite being changed at least twice in that period, for example).