1.: Dive wasnt Meta for a year, it was Meta for ca. 6 months, just like many other Metas like both Doubleshields for example
OG Dive was one of the lost healthiest Metas we ever had. Many people forget because Metas get oversymplified, but during Dive we had multiple comps viable. We had Soldier 3dps Dive, classic Dive, Tritank was still viable on multiple maps and we saw many different Dps
Dps we had: Tracer, Widow, Sombra, Soldier, Doomfist, Genji, Mccree, Pharrah
Supports we saw: Lucio, Zen, Ana in any combination. Even Mercy got used in some situations, if you took Pharrah for example, despite being the worst Support at the time. In ladder she was quite popular. (We had literally wvery Support viable)
Tanks: Winston, Dva in pro play, but on some maps you played Triple Tank too with Rein, Zarya, Dva and in Ladder you played Rein quite a lot
Can you show me any other Meta wich had so much variety aftwr lasting for quite some time already?
(You see: Ana, Zen, Lucio, Winston, Dva, Soldier, Tracer, Doom, Mccree, Sombra, Widow)
(Hereos you see here but not in last one: Rein, Mercy, Pharrah, Bastion)
Your quote "Only 6 Hereos viable"is already wrong because you played already 8 different Dps and 4 Supports