"We came up with the idea to promote scientific related content via ResearchGate questions"
This is awesome. People often think of Google as the main search engine, but trying to get ranked or found by google is so hard. But a search engine is anything that people go to find something and smaller search engines, such as Reseachgate offers a better chance of a good ranking than the bigger search engines. I actually have this on my list as a topic for one of my videos.
50-60% of traffic being organic does not seem unreasonable for a lot of businesses
https://searchengineland.com/study-organic-search-drives-51-traffic-social-5-202063
however as the content on steem is created by so many different people, all with their own reach, we should be able to increase the traffic we get from social with ease