Most eighth Gym Leaders are Elite Four tier, at least up through Gen IV. Green, Wallace, and Iris are Champion tier at their peaks. Raihan would be Elite Four tier if the Elite Four existed in Galar. RR Giovanni is arguably Champion level.
It also used to be that Elite Four order mattered, with each one being tougher than the last. Bruno went from second Elite Four to third Elite Four in 3 years. Lance, Karen, Drake, and Lucian are each considered the toughest members of their Elite Four, and each one is considered wise in a way.
Once they started letting you choose Elite Four order, characters stopped being considered tougher than each other.
