Social Bookmarking is important in 2020?

It is important because most of the people still use social bookmarking sites and resources that become popular on one often grow enormously, going viral because the resources are organized by people and not by search engines. It is also important because of the importance of backlinking.

Social bookmarking is always important for SEO activities. Bookmarking activities helps to generate more traffic to your website.

I don't think Social Bookmarking is helpful in 2020.

Since backlinks play an important role in SEO, as they help you to increase your site's domain authority & traffic, building quality backlinks is very important and by using bookmarking sites, you are able to earn those links, thereby improving your site's ranking on search engine result pages.

Bookmarking is still effective technique of SEO. It helps to increase website traffic  and ranking on search engine.