Smallville is the most stagnant show ever
Especially in it's first seven seasons. It has a multitude of deep format flaws that I'm not sure the writers knew they were creating but if they did they certainly didn't intend for the show to go through any major changes as little did they know it would go on for ten seasons.
Clark and Lana love story could've easily ended after three seasons but they were dead set on it probably because they felt because it's about a young Superman he should be obsessing over his first love for the entire series.
The creators were dead set on Clark not flying until the end but it was like a four season rule and most of the time was making Clark look bad especially when other characters could and made him the most stagnant character on the show and as a result his first flight in the last episode was a bit of a let down for one saving stuff til the end can lead to problems.