They are evenly matched with Russia with regard to quality troops. It doesn't matter how many randos you've in your back country, both countries have a sizeable enough population.

The thing that matters is how many cohesive units can you train and get to the frontlines. That is around 50k troops per half a year. If Russia loses more than that, it will start to have problems replacing troops, like it had when all those videos came out with guys armed with Mosins, or even unarmed, trying to fill in units that sustained hard losses. OTOH Russia is suffering casualties of around 3:1, which it absolutely cannot sustain. If it keeps "winning" as it did in Avdiivka, by the way they get a third of the way to Kyiv, there is no Russian army.

Even with artillery, while they are great at shell production, their quality of guns have declined sharply. They went from 80% self-propelled to 80% towed since the start of the war, and a significant portion of that is WWII D-10s with an effective range of 10 km. Some FPV drones can do more than that.

Point is, Ukraine can totally win if the West keeps up its current level of support. The question is whether it will do that, especially with the US elections that are coming up.