Medium, Quora, and Wikipedia are unique aspects of blogging because they are very high-authority websites. Still, the value of backlinks from them depends upon the level of traffic acquired by the articles with backlinks. To simplify, higher traffic on an article containing your link means higher quality backlink.
In Medium, you can post about your business or some helpful information and link to your website.
Quora helps you answer questions and works on the principle that higher traffic means higher-quality backlinks. However, do not spam your links on every answer; it will harm your website.
Wikipedia is a high-quality source of backlinks, even if they claim to use “no-follow” linking. However, links to businesses and private pages are often removed if they are not widely known websites. I have myself got my IP address blocked by Wikipedia in the process of getting a backlink. Overall it’s a high-risk, high-return game.