Worst Rock Band Ever !!!!

Music categories and labels are somewhat subjective. I consider ABBA to have been not a Rock Band---the OP’s category, but a Pop Group, and a great one. Benny & Bjorn wrote GREAT Pop songs (chord sequences, melodies, harmonies, arrangements, etc.), and the members had good voices, Frida Lyngstad in particular. She has made great music since leaving ABBA as well; watch her You Tube video of the great Jackie DeShannon song "When You Walk In The Room". Glorious! ABBA songs have been celebrated in Broadway shows for a good reason---they're real good ones!

To qualify IMO the band has to have some mainstream success. The Steve Miller Band.has very little to offer😭

... what I think is a great recording/music is the 1st Hoobistank CD; they are pittiful when/if heard live.
As I remember: The Band was rock-solid, recorded or live - almost note for note identical... 

For all the Steve Miller haters, the early stuff was really good, Jacjson Kent State Bles, Gangstr of Love, Space Cowboy, etc.  

I saw them live in 72 if I recall and enjoyed it immensely.

Terrible is the Strawberry Alarm Clock, could not play a lick live.