If you're still struggling to take down Ganondorf in Tears of the Kingdom, Recent-Marsupial-65 might have a solution--fence him up and wail on him with electric spikes. Basically, torture him 'till he drops dead. Who said the Master Sword was necessary?
With stakes, motors, thunder emitters, big wheels, spikes, and just a pinch of trial and error, Recent-Marsupial-65 managed to corner Ganondorf into an inescapable pen before unleashing their contraption. It's basically a fast-spinning spiked lightning mace on a podium level with his head that hits him with every rotation, chipping away at his health until he enters his final phase. And since he's in the fenced-off pen, he can't move, doomed to suffer.
If you manage to pull this off with two of the giant spinning maces, Ganondorf will go down even quicker. There might be a speedrunning strategy to this, but there's the problem of getting him into the pen itself--it takes a lot of chance and luck. But if you want to put it together yourself, RM65 released a more in-depth tutorial video on YouTube that you can watch below.
They start by pre-building a pen and saving it to the auto-build menu. Afterwards, they venture down below Hyrule Castle toward Ganondorf boss arena, but before they enter and trigger both the cutscene and fight, they place down the pen and carry it in with them.
The next part is where the trial and error comes in. You have to lift it up and put it on top of Ganondorf to trap him. Something breaks in his AI and he becomes incapable of moving or attacking. You then repeat this for his second, more aggressive phase. Step two is messing with him, which RM65 does in a variety of ways.
You can build big spiked maces, bring a Hudson cardboard cutout to taunt him, or set up a ramp to roll explosives toward his head. And the entire time, he's helpless to stop Link. We even see a slow-moving sword attached to a wheel slicing at Ganondorf bit by bit, gradually whittling down his health until he finally enters his last phase.
Other options include pointing a laser at his head and grabbing a snack while you wait, shooting him with a bow a bunch, electrifying the cage itself, turning it into a maze, standing face-to-face and dancing naked in front of him, spraying him with water (which won't actually hurt him), and filling the room with random shit until your Switch crashes.