The experience I had using pinboard was very similar to what I have using Chrome and Firefox Bookmakers. As I said, I still have saved pages I used in 1996, I have never had an experience of losing everything. So, the only advantage would be the rankings and the tags trends.
Well, and being able to get at your bookmarks from anywhere, and being able to attach searchable descriptions/tags to the bookmarks so you can find it even if the page title or URL isn't memorable.
Firefox bookmarks support tags, keywords and descriptions. Plus it syncs (encrypted end-to-end), so you can get them anywhere if you can use Firefox from that place.
I use both browser bookmarks (Firefox) and Pinboard. I think they're complementary rather than one being a replacement for the other.
I use browser bookmarks for pages I visit often or intend to return to fairly soon. I use Pinboard for long-term archival where link rot is a real concern.
