LCS Pick and Bans vs Ranked Pick and Bans

Why the inconsistency here?

Okay, I understand Ranked Solo/Duo not needing the strategy as it's a game mode intended for...other purposes?

Aside: I really don't know why Solo/Duo exists in a team based game, shouldn't "Ranked" be 5v5 only since the actual pro-scene is just that? Normals would do just fine for solo players or smaller groups. Can someone explain the actual logic?

Ranked Flex, however, is where actual teams go to play. Can we maybe get the same pick/ban phase in LCS for Ranked Flex to keep some consistency in the 'minor leagues' as it is in the 'major leagues'?