Cardcaptor Sakura is about an elementary school girl named Sakura Kinomoto who has to recapture all of the Clow Cards, magical cards that have special abilities, that she can then release to aid her in battle. In the process, she encounters many obstacles, including the cards often creating trouble at school, home, or other public spaces, as well as her own personal problems, like trying to deal with school and her relationships. At the end of the two seasons of the original anime, Sakura faces-off against two powerful magical beings who devise trials that further her magical growth.
However, these beings weren't actually enemies of hers, meaning that we never had a real villain in the original series, and only had one in the Clear Card arc that came later on. Did Sakura need one? Or were the final episodes of the two seasons enough to convince us of her strength and development without one? Let's look at the first two adversaries Sakura faced in the original series to find out.
Sakura Vs. Yue
In Season 1, Sakura was only just starting to learn magic and was prone to making a lot of mistakes that had some serious consequences. But as the episodes went on, she grew more adept in using the cards more effectively and had truly grown into her own. In the final episode, she battles against Yue in the Final Judgement, in which he determines whether or not she is worthy enough to become the Master of the Cards. If she fails, everyone would lose all of the memories concerning the Clow Cards. Because Sakura has only ever known him as Yukito, the boy next door, she does her best to avoid hurting him. In the end, Sakura is able to prove herself to Yue, regardless.
Memory loss, while devastating -- evidenced when Sakura imagines what her life would be like without her memories of the Clow Cards -- isn't as high stakes as it could be. And in the end, Sakura's magical growth isn't really brought on by her fight with Yue: She just raises her wand and it magically transforms into a star-shaped point. Yue was only there solely for the purpose of testing her. In that way, Sakura's growth feels forced rather than developed organically.
Sakura Vs. Eriol
The following season, Sakura meets a new student named Eriol Hiiragizawa who turns out to be a reincarnation of Clow Reed's spirit. Instead of fighting her, he gives her a challenge: to turn the last eight Clow Cards into Sakura Cards to become the true Master. If she doesn't do it, then the world will fall into an eternal sleep.
Similar to Season 1, there is no fight between Sakura and Eriol, with the conflict more between Sakura and the cards when they refuse to turn into Sakura Cards. Eriol doesn't do much except observe, never really acting like a real threat to Sakura because he was never going to actively stop her.
While this season's finale was much satisfying than the last, with Sakura relying on the combined strengths of Yue, Kero and Syaoran to finally turn the remaining cards into Sakura Cards, it was still rather underwhelming. The reveal of Eriol being Clow Reed, as well as the danger of putting everyone in eternal sleep, would have made the perfect setting for an ultimate fight between former and current master but instead, it was used again as a teaching moment that didn't really teach Sakura anything other than the fact that she's not alone -- a fact she'd already embraced.
Did Sakura Need a Real Villain?
Needless to say, there's no real need to have a villain in order to have a great story, but Sakura's growth in both her character and her magic would have greatly benefited from fighting a proper baddie. It would have truly forced her to dig deep into her powers to see how much she has improved from Day 1 -- from fumbling to capture cards to be able to seamlessly use them as a way to fight on her own. Cardcaptor Sakura: Clear Card gave us that showdown but there should've been one in the original, as well.
Each card that Sakura captures demonstrates her continuing growth as a magician, so having Yue and Eriol set a final trial for her was unnecessary. Yue and Eriol had always been her allies, even when it didn't seem like they were in the beginning. If they wanted her to prove her worth, they could have had an all-out fight with her and let her skills and prowess speak for themselves. We didn't need Final Judgements; instead, we needed Sakura to face-off against an actual villain to truly show how much she'd grown.