I think you describe it well. I play defensively with Chun, but I don't have the knowledge or experience to turn it into my favor. Whereas with Cammy I am able to pressure the opponent into making mistakes and know enough basic combos to make the most of it.Eventually the other player will end their turn on their own. Especially at that level. If you want to play in a more slow manner it requires you to know when your opponent is minus and punishable. Lots of the random tatsus, runs and flips are punishable on block and in reaction. It requires a bit of game knowledge to know whereas with a more offensive style you force your opponent to make mistakes more clearly as you probably score tons of counter hits with Cammy when you're playing offensively with her.
There's also a lack of automaticity with certain actions like anti-airs and walking forward that can hamper your ability to pressure your opponent and control space when trying to play in a slower more deliberate manner.
Lack of automaticity is also definitely a thing. At least I feel all that blocking I did with Chun already did wonders for my ability to react to where I need to block. In the beginning, jumping opponents always caught me off guard in wakeup or corner situations. But yesterday I noticed I was actually able to reliably predict when they were going to do it. I mean, I am in no means a master at blocking or anything. But at least it is something positive to come out of yesterday's many, many losses.