Uh, the Russians have been trying and failing to take Bakhmut since August 1st.They have been trying to take the Kremmenya salient since October 2022. They spent half a year failing against Kherson west bank.
Russian military performance in spring in the offense is approx. a 3.5 out of 5 all things considered. In the summer a 2.5-3 out of 5. Their main issue wasn't infantry losses but losses of vehicles.
You think Ukraine has failed to take Kherson west bank?