The work of those who are involved in SEO depends on many factors. The existence of a single search engine, practically a monopoly in the web search in almost every country of the Globe, is one of the worst obstacles to SEO activity.
The monopoly does not provide for the transparency of the rules of the game. The rules are not written in any where, just a great judge “Google” decides when my action is lawful and when it’s not. The “public” rules can change from day to day and frustrate hours/days of work in a few instants.
We would be talking about a tyranny if we were in a real country but as we are “on the web” you do not say “dictatorship” and we are still here to play.