This is a very narrow view that takes into account only one side and completely ignores the other. Yes, other countries can benefit from supplying weapons to Ukraine. But this aggressive war has already badly affected world markets. Fuel and food prices have risen sharply. All European countries have already experienced this. Business is closing, trade routes are being lost, the tourism sector is suffering. These factors cannot be excluded from the equation. I think they not only compensate possible gains, but also exceed them.
I agree to this because Russia is the 2nd exporting country of crude oil and as we can see the prices have risen up. Thinking about the situation in both countries (Russia and Ukraine) is having selfish mindset because they are not the only one who's really compensating about the changes. Maybe some people might benefit for this situation such as; goods, services etc. but it is only because the damage is too much.