zk antis wouldn't admit this but in the last fight it HAD to be katara beside zuko for not just logistical but also for symbolic reasons which aren't as simple as ~he is fire she is water~

In each finale it was always specifically Zuko and katara against each other except the last when they were together on the same side. Zuko taking the lightning bolt is the flip side to Zuko specifically betraying katara in ba sing se after their bonding in the catacomb

Yes yes yes that's why the southern raiders exists but the southern raiders doesn't imho concern Zuko because it is much more the story of katara learning to heal from her personal trauma. Crossroads of destiny is balanced out by the final Agni kai because

What started out with Zuko taking a fatal step to break Katara's trust ends with him taking yet another fatal step but this time to save the same person he'd betrayed. He earns her trust not by leading her to her mother's killer but by putting his own life on the brink for her.