After iOS 14.5 broke deterministic attribution, Meta's machine learning needs two things to work: enough signal (via Conversions API) and enough creative variety (because audiences are now modelled, not targeted). When either is missing, the account quietly burns budget on Advantage+ that's optimising against a degraded conversion signal toward a saturated audience.
Three failure modes show up in nearly every audit. One: Conversions API either missing or sending duplicate events that Meta deduplicates poorly with the pixel — your reported ROAS is fiction. Two: Creative refresh cycle measured in months when fatigue compounds in weeks; the top three ads usually carry 70% of the spend until they collapse. Three: Account structure built on legacy ABO logic when CBO + Advantage+ Shopping has been the higher-performing default for over a year.
Fixing creative production is the harder problem and the one most agencies avoid. They'll happily restructure your campaigns. They'll run audits forever. But producing 8-12 fresh creative concepts per month — with proper hook variation, motion testing, and UGC integration — requires actual production capacity, not just an account manager in Excel.
That's what a real Meta Ads engagement has to look like in 2026.