Product schema does not directly affect where your page ranks; its real effect is on the rich result and the visibility that comes with it. Marking up a product with price, availability, and review data makes the page eligible for enhanced listings and shopping surfaces, and those richer listings can lift click-through rate, but the structured data itself is not a ranking factor that pushes you up the results page. The honest framing is that Product schema works on presentation and eligibility, not on position.
The confusion comes from watching traffic rise after adding schema and crediting the markup with a ranking boost. What usually happened is that the page started showing a price, a star rating, or stock status in the listing, the listing became more compelling, and more searchers clicked. That is a CTR and visibility gain on the same position, not a move to a higher position. It is also why two pages with identical schema can perform very differently: the markup only opens the door to the rich result, and Google still decides at its discretion whether to show it.
There is a second, indirect path worth naming so you do not undersell it. Product schema can make a page eligible for surfaces it otherwise could not appear on, such as shopping experiences and merchant listings, and presence on a new surface is genuinely new visibility even though it is not a higher rank in classic search. So the value is real, it just lives in eligibility and click-through rather than in the ten blue links order. Treat any specific CTR figures you read as working estimates that vary by query and industry, worth re-checking against your own results.
For your next product page, add complete, accurate Product schema because of what it can show in the listing, not because you expect it to rank you higher. Make sure the marked-up price, availability, and reviews match exactly what a visitor sees on the page, then measure the change in click-through rate rather than position to judge whether the rich result is actually appearing and earning the click.