Not surprising. Before the war there were many who considered themselves Ukrainians and Russians, then when Russia invaded they had to pick one or the other. Reminds me of how British and Irish used to not be conflicting adjectives. Of course in addition to those Ukrainians who fled into Russia willingly, there are also those who are just being coerced abducted or lacked a safe route into Ukrainian held territory
Analysts were claiming, before, that war losses and emigration would destroy Russia's economic future.
War losses and emigration are gutting very specific demographics in Russia. The war is mostly killing young men, and a huge portion of the people leaving the country are not only young but highly educated. A nation made up largely of old people and children is likely to be economically crippled for a generation or more - Europe after 1918 (where basically every country had spent four years feeding their finest young men into a sausage grinder) lagged heavily behind the US (who were "only" able to send 6-7 million men to the front before the war ended, and a lot of those didn't even see heavy action) even before 1929, and the Great Depression hit far worse there.
Russia isn't losing nearly as many people in combat, obviously, and emigration (which, from what I can find, is estimated to approach or exceed one million souls) is only hitting a fraction of the WWI losses (somewhere around three million dead, combining soldiers and civilians) in absolute or proportionate terms, but there are two factors that more than offset the raw numbers. First, it isn't
just young men that are vanishing in large numbers. Quite a lot of women are leaving as well, creating a more complete gap. Even more importantly, they're suffering this loss while none of the other economic and military powers in Europe are. That makes the wound far worse because it isn't a case of everybody else being dragged down as well. It's just Russia (and Ukraine, obviously, but it would be a long time before they were a major economic player even without the war) that's taking this hit.
Ukrainian refugees can't offset that, even if the claims of raw numbers being greater (which I can't find to evaluate) are accurate. Many of those refugees aren't adults, and (more importantly) most of them are not in Russia voluntarily. They're not going to go one step beyond whatever they need to do to survive.