Ehm genuinely question how?
Except being humiliated and used as a punching bags, they have been embarrassing.
Given the possible fact, that the Gorosei don‘t exist and perhaps being the power of Imu, they won‘t even be relevant by themselves anymore.
Trust me I absolutely cheered for the Gorosei, but Oda just consistently showed us how shit he is and especially him threating his antagonists like ants.
Only Saturn was a punching bag, the rest were all fine.
They still accomplished their goals of getting York, getting the Mother Flame, getting Punk Records, killing Vegapunk though Kizaru, and killing Emet.
The only thing they failed on was killing the Straw Hats which can you blame them for that, and failing to stop most of Vegapunk's message.
Heck they still prevented Vegapunk from saying anything about the Will of D and they stopped the message at the last moment before he could say anything else.
The Gorosei do exist, they might just be split off from Imu, similar to how the Satellites are clones of Vegapunk.
They will still play a role in the future.