@sailorleontine , I think Fairies weren't added to the Sims 4 by the time you started playing in 2020 was because they had so many ideas they wanted to implement. They had all the usual themes for packs that had been in previous versions of the Sims like Seasons, University, pets, social activities/cities, being a celebrity, and jobs you could join along with your Sim; but, they also had new ideas like Strangerville, Eco Lifestyle, Parenthood, Outdoor Retreat, etc. And then they took a new twist on old ideas by separating supernatural types of Sims into their own packs. Aliens have always been a part of the Sims (Sims one didn't have the actual Aliens, but you could get abducted) and Vampires are usually the most asked for. Other than ghosts (which we had in every version since Sims 1) which came early on in the Sims 4 in the base game, the most asked for supernatural Sims were witches and mermaids. I do wish we had Mermaids separate from the Island Living Pack , as well as Aliens separate from the Get to Work pack , so that they could be as detailed as the other Supernaturals in Sims 4. But I'm very happy they separated Vampires, Werewolves, and Spellcasters (witches).
But since not everyone likes to play with supernaturals, they have to intersperse the packs with normal things like Parenthood, Seasons, Cats & Dogs, etc. So that is why it has taken so long to get Werewolves and would take even longer to get Fairies and/or Zombies. 😅
Well, out of my 3 favorite things about Sims 3, one of them was the Fairies! (the other 2 were the CASt color/pattern tool, and the Pets EP with dogs and cats that you could control , as well as horses and unicorns! ) And while there were other things I enjoyed about Sims 3, I didn't like it as much over all compared to Sims 4 and especially Sims 2🥰🥳 !!! (Hard to compare it to Sims 1, since you couldn't age in that game, and children couldn't become adults unless you used a magic spell, but then they would probably not resemble themselves as children! 😅 But I think I even like Sims 1 better than Sims 3. Not a popular opinion! 😅😜 ) The Sims 3 open world was usually devoid of other Sims activity (in Sims 1, 2, and 4, when I visit a commercial lot, no matter what time, there will always be other Sims there to interact with!). I also had a bad time with Sims 3 lagging, outright stopping for long periods of time, and frequent crashing. The Sims 2 is still my favorite!