Attribution without watertight measurement is a model built on sand.

Every attribution model works with what has been measured. If a channel is missing, a conversion is counted twice or the values are missing, the result is neatly formatted nonsense.
Meta and Google both claim the same conversion, each by their own rules. Add them up and you end up above your actual revenue. That's why you need one source that looks across channels — usually GA4 or your own system.
Measuring twenty events nobody looks at costs maintenance and delivers nothing. We limit it to what can change a decision.
A question or project on this topic?