Code Search Engine Optimisation is dying

I have been doing Search Engine Optimisation (SEO) for a few years now and have seen a big change that could be for the best, or for the worst.

Responsive decided

The battle field was laid out and the fight between the quick, safe, easy  fixed viewport and the reliable, standard responsive viewport was a foot. Then walked in the boss… Google. Recently Google has decided which method you must follow to get good rankings on its search engines. Is it the best choose? And should Google get to decide?