Russia is set for a long term very slow decline and I can prove it.

Note:

It won't be as fast a decline as China.

There is very likely going to be a forever war in Ukraine lasting many more years.

Here is my proof:

Russia's war economy has left Russia short of 4.8 million workers - https://www.reuters.com/world/europe/russia-short-around-48-million-workers-2023-crunch-persist-izvestia-2023-12-24/

Russian GDP growth for past five years averaged 1.32% per year. ( 2.2 + (-2.7) + 5.6 + (-2.1) + 3.2)/5 = 6.2/5 = 1.32% per year - https://data.worldbank.org/indicator/NY.GDP.MKTP.KD.ZG?locations=RU

Russian GDP reached a new peak in 2023 - 2,240 + 3.2% = 2.311 trillion USD - https://www.worldometers.info/gdp/russia-gdp/

Russian population peaked in 1993 at 149 million people. - https://www.bofit.fi/en/monitoring/weekly/2024/vw202409_1/

Russian artillery production is high but Ukraine is still getting better equipment - https://apnews.com/article/ukraine-nato-summit-patriot-air-defense-6bf639e3a76e9ea8adbdadabd2660490

Russia's robot density is 6 per 10,000 workers, so the declining population is not being balanced out by robot production. - https://tadviser.com/index.php/Article:Industrial_robots_in_Russia

Russia is increasing trade with India and China, both economies big enough to allow Russian economy to stay in business for the years ahead. - China economy - 18 trillion GDP. India economy - 3.5 trillion GDP. Russia economy - 2.5 trillion GDP.

Russia's median age is 39.2 years now. - https://www.worldometers.info/world-population/russia-population/

Russia is giving citizenship to 100,000 plus Tajikistani workers per year now. - https://eurasianet.org/tajikistan-as-expat-worker-life-gets-harder-russian-citizenship-tempts

Hundreds of thousands of Russians may already be dead in the Russia-Ukraine war - https://www.express.co.uk/news/world/1920357/russia-army-casualties-update-ukraine-war

Conclusion:

Russia is using every single point in its favor to try and win this war. Russia is suffering from a labor shortage that is likely to worsen as long as the war with Ukraine continues. Tajikistan is not a large enough nation state to supply all the labor needs of Russia even if Russians keep accepting Tajikistan nationals as citizens at current rates.

Russia's economy will not collapse due to lack of markets to trade with, however Russia's demographics are going to continue to worsen along with increasing labor shortages over time. The two nations poor enough to keep sending people to Russia are Tajikistan and Uzbekistan. The combined population of these two territories is 45 million people. Both of these regions are growing at a fast enough rate economically that the flow of citizens to Russia from these regions is only going to slow down year on year at a rapid rate.

Russia's demographic decline will not be as extreme as other East Asian economies due to being open to immigration from Central Asian nation states, however, Russian economy also does not have the support network provided by mass usage of robotics in their manufacturing industry, meaning that their GDP growth will consistently decline as their overall population declines over time.

As Russia is using every single trick it can to stay afloat, while conducting a forever war in Ukraine, it becomes safe to conclude that Russia's decline will be glacial and guaranteed.