Title. Typically there's always been a dominating agent (Chamber, Skye, Astra, Harbor/Viper, Tejo) but this meta feels very heavily balanced (maybe a bit biased towards Omen and Viper).
We're also seeing teams choose between double duelist/ini/controller/senti based on their players and play style, leading to diversity. Teams like PRX and KRU might incline towards double duelist whereas teams like Sen might incline towards double sentinel or double controller due to their player styles. This might also be why G2 (once Leaf is back) and Fnatic seem so strong, because they can switch between double anything due to their player versatility.