The only reason I think it's a cop-out a small one though is because it is just a excuse to not make them all in one singular timeline.I still don't care much about theory I just play the games but I wish it was easier to understand.
The split itself is not that hard to comprehend. Link goes back to his childhood and leaves the time in which he defeated Ganon behind, in the process having two separate times that run parallel to each other. The time Link returned to branched off of the time he left behind. I don't see how that could be so hard to understand.
I can't really agree that the child timeline leads to the events of Twilight Princess. It more leads to the event of the wind waker because if you remember in the wind waker's prologue, It explains that Link traveled in time to seal the dark one away.
Link never sealed anyone in TP. Ganondorf died at the end of that game. He
did seal Ganon in OoT, though. But only on the time he left behind. When he returned to his own time, he went back to before he ever met Zelda. That time around he never opened the Door of Time. Eventually, Ganondorf was chased out of Hyrule. After some time, the "divine prank of thegods" happened, meaning the Triforce split on its own, giving the three parts to Link, Zelda, and Ganondorf. Ganondorf was then later sealed in the Twilight Realm by the Sages after failing to properly execute him, due to Ganondorf having the Triforce of Power, which prevented him from dying. This is the backstory to Twilight Princess and occurs on the Child Timeline. Nothing happened in-between OoT and WW, as there was no hero to stop Ganon when he broke out of his bondage. The reason for this is because the Hero of Time returned to his own time and couldn't return to the time he left behind. That is how the split works. It is confirmed by Aonuma that TP "runs parallel" to WW, meaning that the games are on separate timelines. Saying that TP comes before WW is a direct contradiction to that.