At the start of Feb 2025 USD was 100 RUB, a few days ago it was 85 RUB. Does this mean their nominal GDP grew by 15% in one month? In some cases it's fine to use Nominal GDP while in other cases, you should use GDP PPP instead. When you look at PPP figures, Russia's economy is on par with Germany or Japan. https://en.wikipedia.org/wiki/List_of_countries_by_GDP_(PPP)
Anders Puck Nielsen just published an interesting video on this topic [How does Russia's military spending compare to Europe?](https://www.youtube.com/watch?v=rxq-TvgNCBU)