It’s actually even more interesting than that.
You see, in 2018 OWL, they were expecting stage 4 (scheduled to start on May 16th) to run on patch 1.23, which was the one with the reworked Hanzo (Storm Arrow, Lunge). Expecting that, all teams started scrimming with one of their players becoming a Hanzo specialist, and working strategies around Hanzo and stuff.
However, they found out a bug that would affect all escort maps in case of a forced pause, thus, forcing the stage to be played on patch 1.22, with the old Hanzo that we all collectively agreed that was a troll pick and worthless of a party slot. But since all teams were working so hard around Hanzo, they started using Hanzo anyway. He was one of the top DPS picks of stage 4, and key to many teamfights, even outside of DragonBall combo.
And he did that without needing a rework, at the first opportunity the pro players just decided to utilize him in the team.
Pair that with the perception that during the height of dive, Reinhardt was considered too weak and “desperately need buffs”, but now six months later after receiving a grand total of zero buffs, and is seem by the community as “too powerful” and “mandatory in every team”. And then you notice how people simply mirror pros without understanding how the game they play are different from the game we all play, and how efficiency within a coordinated team is different from efficiency in a team of 6 wild cats running in 7 different directions.