For years now I have used "-pinterest" on every regular search term I utilize (I bake that into any Google bookmark). Would applaud the removal of Pinterest from search results.
Google has given up on improving search, much like Microsoft did with IE6 when it became the dominant player. Only real competition would force them to start improving again.
Here is my own userscript that removes any matching URL portions from Google search. It does it in a fancy way with stylesheets so that you never see the Quora, etc results even temporarily before they're removed. It also fixes Google Images to link directly to images again, removes all the tracking URL obfuscations, and more.
I only use the script on my desktop, and so I've never seen an AMP result. I'd need to be able to use the 'inspect element' developer tool on mobile I suppose in order to see how to filter them. Not even sure the script works on mobile though.