Putin wakes up every day and chooses not to. He could, and that would make sense in some ways, but at the same time it also would mean that he loses entire support and gets sent to Hague. And this is something he would very, very like to avoid
This war was launched to bolster approval ratings essentially. This worked in 1999, 2008 and 2014, and even for first few weeks in 2022. Walking this all back after banking all support on nationalist segment would be political suicide, and this is not something you do when your primary goal is to cling to power forever