To be clear, it seems like two different datacenters, and the first attack alone seems to have been wildly successful already, burning down ~1/3rd of the entire building (!!!). Some of the reported outages:

  The most serious disruptions were reported in Moscow and St. Petersburg, where users also experienced problems with T-Bank, internet provider SkyNet, and the Mango Office cloud service... Yandex Disk, Yandex Documents, and other company services... online bus-ticket sales in the Moscow region [via] MosTransAvto... Several major Russian media websites, including RBC, RIA Novosti, Kommersant, Vedomosti, Interfax, and Vesti... Russian Railways...

And all that's before this attack. We'll see what the extent is, I guess.

So I'd say the goal here is to intimidate and/or inconvenience the Russian public and general economy, which is the main way they'll advance a war against a country they are forbidden from invading to any semi-meaningful degree (due to nukes). Permenantly destroying data would be nice, sure, but service interruption is already such a huge win that it'd be a marginal improvement only, IMHO.

That is, unless there are cloud-native banks without backups, which... yikes! Possible, I suppose?