I disagree with the premise - I think the series as a whole stands as a testament to the Federation prevailing over adversity - it's one of the prevailing themes of the series.
Even the Burn didn't destroy the Federation as you suggest. It became smaller as travel and communication became difficult-to-impossible, but it still existed, and Starfleet was doing everything it could to maintain the peace.
Despite the series' popularity with...people like us, I don't think the numbers were where Paramount+ wanted them. It seems like they have issues with animation in general, which is a damn shame.