The others mentioned the improved financial situation and development of longer range drones.

The Russian advances have stalled since the start of the year indicating that the war was already close to a turning point. And Ukraine has been hunting down Russian air defenses for well over a year now with success.

Basically, Ukraine now has the technology, the finances to produce the technology, diminished the countermeasures against the technology, while the war reached a point where Russia no longer can reliably resupply their countermeasures. It can only get worse for Russia at this point as long as Ukraine continues to receive sufficient finances and materials.