Although Ukrainian progress has been slow, they are finally making important gains and are going in the right direction. War doesn't operate in a linear fashion — defenders may be able to hold for a long time, but when the levee breaks, attackers can make swift progress. There's no reason to believe that Ukraine can't do the same.
While Ukraine is making incremental gains, it's quite clear that it won't succeed in pushing Russia out of all of the four territories it's claimed to have annexed, let alone Crimea, which was taken in 2014. Now is the time to formulate an achievable endgame to the war — one that also takes into consideration Russia's point of view — to avoid the conflict from erupting once again.