Linkedin does not like the traffic that goes outside linkedin, so i use linkedin for business and write short exclusive to linkedin post in order to interact with the people and make business. They go to your website, but that does not have a great impact in my SEO at least. Also is true i don't drive thousand of people, market is really small here and im the number 1 million Digital Marketing agency here, so is saturated. But you can use linkedin to make a name, people will ask for you, and visit your website.
Write interesting posts that can reach at minimum 2000 people and die very fast, and publications (i wonder if that is the english name) that last forever but reach not that much people, and also the efectivity is not forever it last for a month+ if is not really popular.
In conclusion, no, is not good for SEO, dont waste too much time on linkedin if your target is the SERP, but invest enough time if your target is doing business.
Edit: If you need the backlinks, use the coments, and never the post itself, in publications you can use a link, but i'm not sure 100% if that impact the reach of the publication. Every link that is in your post should be directed to another linkedin page, and every external link, should be made in coments. That is how i do it at least.