I've spent a fair amount of time in the analytics trenches - GTM, GA4, Screaming Frog - and the more data I look at, the more I'm convinced marketing is just applied psychology with a budget. You're spot on that it's not about clever ideas in isolation, it's about understanding the user's mental model and then aligning your value proposition with that model. if you're not mapping your messaging to what the audience actually cares about, you're just shouting into the void - and the analytics will show you that void very quickly.
On the manipulation point - yeah, that word tends to be a signal fire. from a purely technical standpoint, any time you're optimising a landing page or A/B testing a CTA, you're systematically influencing behaviour. The difference between "persuasion" and "manipulation" is often just a matter of transparency and intent. but as someone who's built tracking for dozens of brands, i can tell you that the most effective campaigns are the ones where the user feels like they made the decision themselves - even if you nudged the path. That's the art.
One thing the original thread didn't touch on: the best marketing today is built on a foundation of data integrity. If your tracking is broken, your understanding of the audience is an educated guess at best. i'd argue the sole purpose is measurable value delivery - and you can't measure it without clean implementation