This isn't true.
Putin laid out several objectives of the SMO, which were to "demilitarize, de-Nazify" Ukraine, and prevent the expansion of NATO.
"Demilitarize" is an uncertain term; Ukraine certainly still has a military, but this may also be not entirely literal (a decimation of capabilities rather than complete elimination), so I'll leave that one open ended.
"De-Nazify" is meaningless; Ukraine is not a Nazi state, is headed by a man of Jewish descent, and does not subscribe to Nazi ideology. However, given that Putin labeled the Zelensky government as "Neo-Nazi", this lends credence to the idea Putin seeks the dismantling of the current government in Kiev. that has clearly failed.
Preventing the expansion of NATO clearly backfired, as instead it has expanded to include Sweden and Finland.
"protecting ethnic Russians in Donbas" goes hand in hand with the argument that Ukraine was conducting a "genocide" of ethnic Russians in Donbas. Since this is nonsense at face value, it's not an achievable goal to begin with, because there never was a genocide.