Most SEO audits are a crawl export with a logo on it.

Why the big report is the tell

A crawler will happily report two hundred thousand missing meta descriptions, forty thousand images without alt text, and eleven canonical tags pointing at a redirect chain. A report that lists all of it, sorted by how many URLs each issue touches, has told you nothing you can act on, because the two hundred thousand descriptions probably do not matter and the eleven canonicals probably do. Volume is not severity, and a report that confuses the two is a data dump wearing an audit's clothes.

The length is not a sign of thoroughness. It is a sign that nobody did the hard part. The hard part is reading the list a crawler produces and throwing most of it away, because the value of an audit is entirely in what got left out and what got ranked to the top.

What an audit is actually for

An audit answers one question: what is this specific site's problem, and in what order should it be fixed to get the most back for the least effort. That is a judgement, not a crawl. It needs someone to look at what the site is trying to rank for, what it currently ranks for, where the gap is, and which of the ten thousand technically-true issues actually sit on the path between those two things.

Nine times out of ten the answer is short. A handful of pages are not indexed and should be. One template renders its content after the crawler has given up. A migration a year ago dropped a set of redirects and nobody noticed. The thing costing the most traffic is usually a small number of specific problems, and a good audit is the document that finds them and ignores the rest. When the problem is clearly technical to begin with, the technical audit goes deeper on exactly that layer and costs less, because you are not paying to confirm things you already know.

The number that matters is what you do afterwards

A two hundred issue report has a predictable fate: it is opened once, it is overwhelming, and it is filed. An audit that names the eleven things worth doing, with the cost, the risk and the likely return of each, gets acted on, because it is short enough to be a plan rather than a wall. The measure of an audit is not how much it found. It is how much got fixed because of it.

This is also why an audit and the fixing are different jobs, priced differently. The audit is the diagnosis. What it produces is a ranked list a developer, or we, can then work through. If a report cannot be handed to someone and worked through in order, it was never really an audit, whatever the cover page said, and it is usually cheaper to start again with a straight diagnostic conversation than to try to act on it.

The general lesson

Beware anything in this field priced by volume, whether it is links, words or audit pages. The valuable part of the work is nearly always subtractive: deciding what not to do, what does not matter, what to leave alone. A crawler cannot do that, which is exactly why the report it produces is long, and exactly why a long report should make you suspicious rather than impressed.