The creation of profiles on different platforms is a good strategy to get backlinks to your website or blog. In these profiles, you not only add the link and that's it, you can talk to others about your product or service, or about yourself!
These backlinks are very useful to show the online presence of your blog on different platforms. Using this method you can put all your description about yourself and in most platforms you can also add your social network accounts, so you will also help to spread them. And most importantly you will also have space to add the URL of your blog or website.
These links are free and there are some dofollow and others nofollow since you have to try to have a link profile as natural as possible
Another important thing is that this type of sites also improves the domain authority (DA) of the websites they link to, so I suggest you keep this type of links if you really want to improve your ranking and the domain authority of your blog or Web page.