Which begs the question: Why mix logic with templates?
If you're instead thinking more broadly in terms of "structure vs layout", I think the same reasoning for using something like tailwind css or higher-level web components may apply: i.e. the material you interact with is closer to your problem domain
Embedding loops and if/else logic in htmx tags creates scenarios where the content is potentially modified in the rendering step, meaning you can't rely on just looking at the data the backend sent over the wire to determine the source of a result that renders incorrectly. Instead of having control flow in one place, and a single source of truth, it creates an additional point of failure.
Stock price showing up wrong? That might now be a problem in your backend logic or in your complex htmx engine, buried in some template tag.
Edit for clarification: The context holds the data that is rendered as-is by the templating function. So any transformations from the "raw" database data and the context data happens beforehand and the templating function just turns it into HTML.