It will take a while for IceFrog and Valve to tune the facets on all heroes.
Also, it is a bit of a strength hero or tanky hero meta.
The heroes have been picked as the best performing ones from the Divine and Immortal brackets.
The choice of heroes has been made from a combination of high pick rate and high win rate heroes.
So by level 10, he has 7.5% heal amplification.
Oracles other facet is Clairvoyant Curse, which gives him 0.75% spell amplification per level.
The Rogue Knight can keep absorbing damage while helping his team do the same.
His Aghanims Shard upgrade just bolsters that ability with the passive armor and movement speed.
Also, he can be flexed as a support and core, which never hurts.
This has made him a hero that prioritizes maximizing strength, which automatically gives him intelligence.
And with the Quick Wit facet, he also gets attack speed to add to that!
Dark Seer is probably the only hero that makes such good use out of building on just one attribute.
Her facet, Tailwind, is one of the highest picked facet in the game and for good reason.