The threat that North Korea poses to the rest of the world has also been minimized partly as a result of its isolation (whether self-imposed or otherwise). To the extent that the Russian economy deteriorates through isolation, its reduced ability to wage conventional war is a benefit in and of itself.
While probably true, the current goal is to help the people of Ukraine. Helping the Russian people may be a good goal once this job’s complete (although I’m not sure what the current overall Russian sentiment is toward the situation).
I wouldn't support 75 years of isolation in Russia, but a country in free fall might lead to regime change in the not-too-distant-future. I want Putin out. I can see scenarios by which he's out in weeks, months, or a few years.
Even more, I want Lukashenko out before Belarus is a nuclear power. Right now, we could affect regime change without nuclear consequences. That option leaves the table soon.