Help me understand why that’s a bad idea. Wouldn’t that have been more effective at crushing the Russian economy in the early days of the war? That would’ve also invested massive amounts of money into European markets.

Those, who manage to do it in time, wouldn’t face sanctions. The time window could be larger, or even extended to the present day. A further condition could be donating a certain sum to the Ukrainian forces.

In the early days of the war and with Russia being cut off SWIFT, the expectation was that the Russian economy to collapse soon. A way out would’ve made people eager to sell their assets, even at an undervalued price, to salvage at least a part of their fortunes.

Not everyone would’ve managed to do it in time, but that would’ve crushed the rouble and create widespread panic in the country. Of course, the deadline could’ve been extended beyond 30 days later on.

What actually happened, is that some oligarchs did move to the West during the war (e.g. Friedman, Usmanov) but then had to return to Russia, because they were sanctions so heavily. They then reinvested into the Russian economy, because they didn’t have a choice.