Are archons always the strongest of their element? Definitely not. It may be hard to claim that Venti or Morax are the strongest of their element when Xiao and Itto exist as two of the top dps units in the game.

For Raiden, there may be a stronger case to say she is the 'strongest' electro. But even then, she faces some competition too: Yae can deal more off-field damage, while even Cyno has higher on-field personal dps. Raiden becomes very good in driving hyperbloom and national teams.

Nahida perhaps has the easiest time claiming the title of 'best dendro'. The only other dendro unit comparable is Alhaitham, whose advantage is higher on-field dps and dendro app rate.

Who is the strongest hydro? Hydro just happens to be an example of a very decentralized element, with no clear contender for number one. Childe has very fast on-field app, Yelan/XQ have useful off-field app, Mona has high buffing abilities.