Ask Why does SEO advice from different experts always seem to contradict itself?

[Newman]

SEO, which stands for search engine optimisation, is the practice of making a website show up higher on Google. The reason experts seem to contradict each other is that Google does not publish its full set of rules. Nobody outside Google knows exactly what makes one page rank above another, so experts test things, observe results, and form their own conclusions. Two experts can run different tests and come to opposite conclusions, both based on real evidence. Google also updates its system regularly, so old advice can become wrong. In your opinion, does the lack of clear rules from Google make SEO harder than it needs to be?