From reading this thread it is clear that the terms SEO and ESO are being confused.
SEO - Search Engine Optimization and relates to optimizing a website so it can be found in searches undertaken on search engines like Google, bing, Yahoo etc.
ESO - Etsy Search Optimization and relates to the optimizing of product listings using tags and titles.
The two are different, but both Google and Etsy give you guidelines on how to achieve good results in searches.
As that advice given is core to the algorithms used, if you follow their advice you should be fine if minor changes in algorithms occurs.
If you notice most of the changes to Google algorithms are to weed out websites that use the techniques developed by some of the shady "Black Hat" SEO consultants.
The more shady SEO consultants come up with techniques of trying to exploit parts of the algorithm so their client's website appears on page 1 of Google searches.
Google identify the methods being used by such SEO consultants and then Google penalize the websites that use them.
So website owners panic, the shady SEO consultants say it is a change in the Google algorithm, the website owner then pays the SEO consultant more money to try and beat Google again. The cycle continues over and over.
Meanwhile, the small business owner who follows Google's advice (
https://support.google.com/webmasters/answer/35769) rarely gets affected by the algorithm.