Plus he figured he had done enough damage to American politics. You have to also remember that russia has been beating us down with cyber tactics for the last 5 years, even to the point where they were greatly contributing to Bidens approval numbers being down (people are sheep and if every time they log in, they see accounts talking trash about Biden, it will influence them).
Anybody that's watching has noticed that since Biden brought the hammer down on Russia, that all of those accounts have magically disappeared, and all of a sudden, Bidens numbers are surging.
Putin didn't expect the strong sanctions that would cut him off from being able to directly influence internal American politics. If he still had the ability to manipulate us, he would be using the Republicans to wage war on Biden, which would have had him having to defend America on the world stage while also defending himself domestically.
But Biden is completely freed up to pour every ounce of political will into hurting Putin and hurting Russia. It's beautiful.