I read somewhere that statistically speaking Instagram has more than 50 x more engagement than twitter. This has certainly been my experience, every time I post on Instagram I get some sort of reaction, whether that be just someone liking the photo or commenting. That is certainly not the case when I tweet.
Having said that, I think it is a bad strategy to use one social media platform to "drive" traffic to another social platform. If somebody is on Instagram, it is because that is where they want to be in that moment. Why try to drive them out to be somewhere else?
Personally I use Instagram to post any particularly attractive photos of yachts or yachting events and also to post behind the scene photos of videos in production. I know that a healthy number of my subs also follow me on Instagram, so I see the Instagram platform as a way of staying on their radar even when they do not want to be watching videos on YouTube. Added to that, now that I have rebranded my channel I hope that my logo will be more recognisable and my Instagram followers who do NOT currently watch my videos will be more inclined to check them out when they are using YouTube and see my logo.