Ukraine could never be under Russia’s thumb.
The only reason the only other fully European ex-Soviet state, Belarus, is is because they never lost their original post-Soviet leader.
Ukraine ditched first Kravchuk and then (with difficulty) Kuchma.
And later Yanukovich.
Since then Russia’s actions have only driven the country further to the west.
There is I suppose a bleak scenario where Putin tho is he can bomb the place to bits and ethnically cleanse it. Causing a refugee crisis in the west and moving in compliant Russians to take their place.
I think he’d do that if he could get away with it.
Putin tho while he may have no moral compass, presumably likes a nice life.
Stability at home and a comfortable retirement in his Black Sra palace eventually