IF this is true, could be for any of the following:
1. Keep Russia’s population from learning the truth of Putin’s war atrocities.
2. Make retaliation to their own cyber-attacks impossible.
3. Keep their state and business secrets from being compromised by non-Russians.
4. Keep their peoples’ emails, texts, social-media accounts from being exploited by western intelligence to “eavesdrop” on Russia’s public sentiment.
At least those seem to be the most pressing needs from where I sit.