The reason the war has taken so long is that with drone warfare,
No, drones became more important after 2023. Up to the summer of 2023, this looked like a positional trench war with lots of artillery duels, to extent that both sides were running out artillery shells and the entire NATA didn't have a sufficient quantity of artillery shells to send to Ukraine.
The real reason this war took so long is that Russia did not suppress Ukrainian air force and air defenses in the first few weeks like USA and allies did with Iraq in the beginning of the first Gulf War. It could have been a game over for Ukraine if Russian air force could bomb with impunity the front lines and say fly over Kiev.
Without air superiority, the war turned into a slow grim trench meat grinder, and drones made it even worse.