I'm not quite as cynical as to say the *only* reason this is continuing is to drain Russia and the west doesn't give a fuck about Ukrainians whatsoever, but forcing Russia to expend a bunch of hardware is definitely a part of this.
Thing is, most of their hardware's old and crap anyway, they've re-organized the military significantly since the start of this thing and are going to be more powerful after it than before it, and production's amped up bigtime anyway. It's not a winning strategy for the west, especially when you've got China & NK providing them with all the low-level expendable shit a country could ever want in wartime.
There's genuine affection for Ukraine in the west and a principled stand on "you can't just go take another country, post-1945". Thing is, that's horseshit and a bunch of countries have done that post-'45 anyway, might is right at a certain point, national interests are all that matters, and there's always a winner and a loser.
Russia's going to be the winner here, because we're not willing to kick into World War 3 mode and kill millions over "basically-Russia-anyway/Russia Jr". The western part of Ukraine will stay Ukraine, the eastern part becomes Russia, Ukraine will never be let into NATO, and Putin gets his buffer zone on a condition of "never be dumb enough to go into Poland or we WILL fuck you up this time." from NATO. That'll be the score here in a year or two, bet on it.