What the Activity Log actually shows
Open a product's activity feed (or the store-wide Activity Log under Settings) and you'll see entries like "Product updated," "Product unpublished," or "Product deleted" — each with a timestamp and a source: a staff account, or an app's name. That's genuinely useful for answering "did something happen, and roughly when."
It is not useful for answering "what did the price used to be." The entry doesn't carry the old value, the new value, or even which specific field on the product changed. "Product updated" could mean the title, the price, the description, or all three — the log doesn't distinguish.
Why the gap exists
The Activity Log is built to answer a narrower question than most merchants assume it answers. It's an event record: something happened, this is roughly what kind of thing, this is who or what triggered it, this is when. It was never built to be a second copy of your product data.
Storing before/after values for every field on every change is a different job — it means keeping a running baseline of every tracked field's current value, and writing a new row to a change log every time one of those values differs from the baseline. That's a continuously-running comparison, not an after-the-fact note that "an update happened." The Activity Log does the second thing. It has never done the first.
What this means in practice
If a product's price looks wrong today and you don't know when it changed or what it used to be, the Activity Log can only tell you a change event exists (if it's recent enough to still be listed) — not what the price actually was before. The same is true for a title, description, vendor, or inventory policy: the event might be visible, the values involved are not.
The only way around this is something that was already watching the specific fields you care about before the change happened — recording a baseline and comparing every update against it going forward. A record of the event after the fact cannot manufacture a value it never captured.
The honest takeaway
The Activity Log is not broken and it is not missing a setting you can turn on. It is doing the job it was built for — an audit trail of events — and that job does not include field-level before/after values. If that's the specific gap you're trying to close, it needs a tool built for that gap, running continuously, rather than a setting inside the log you already have.