I commented here some time ago on the same topic that most economists didn't predict a sudden collapse in Russia (although some media have been trying to convey such a message).

One of my favourite elaborations is an interview with Russian economist Natalia Zubarevich in 2023 who said back then about Russia, ‘There Will Be no Collapses, but Rather a Viscous, Slow Sinking into Backwardness’. It's an exceptional interview in my opinion with someone of deep knowledge of the Russian economy. Many of the things we have been observing in the last three years have been predicted by Ms. Zubarevich in the second year of the invasion.

In a recent interview from this week, How the War and Latest Western Sanctions Are Impacting Russia’s Oil Sector, Sergey Vakulenko, a senior fellow at the Carnegie Russia Eurasia Center, argues in a similar way when he describes the situation in Russia's oil sector.

Because of the war, the oil and gas industry is, first of all, facing serious problems in terms of refining. Looking at refineries, no one-off Ukrainian drone attack has caused long-term damage. But repeat, larger-scale attacks could create a situation where, at some point, it will no longer be possible simply to patch up or repair distillation columns – they will have to be replaced entirely.

If a person is hit once, even quite hard, he or she most likely will not die. But if a person is beaten regularly, he or she, generally speaking, can die. It is not a knife stab to vital organs, but regular beatings from which people can die – not right away, but over time. Moreover, all this diverts money and resources ... Theoretically, this could be solved with a sharp increase in investment [in the oil industry]. But then the Ministry of Finance steps in and says: no, we cannot afford to take less rent from the oil sector. The money the oil sector could invest in maintaining production levels is now needed for other purposes, and taxes will not be cut.

And in a chapter in the 2023 book on "Russia's Imperial Endeavor and Its Geopolitical Consequences" (highly recommended read), Hungarian scholar Dóra Győrffy concludes (opens pdf):

The relative certainty of the long-term decline of Russia stands in contrast to the uncertainties surrounding the prospects of post-war Ukraine. While success is far from guaranteed, Ukraine has a window of opportunity to leave its post-Soviet patronal structures behind, and build a resilient democracy, rule of law, and a strong market economy with Western support. The return of refugees, the inflow of Western capital for reconstruction, access to technology, assistance in institution building, and a strong social commitment to the idea of freedom provide a strong foundation for a new Ukraine embedded in the transatlantic alliance. Achieving this vision is the shared hope and responsibility of Ukraine and the West in their fight against autocracies.