As @Dutchie Abroad
(wisely) said; using Instagram to promote a YouTube channel doesn't work, in fact generally speaking using one social media to promote any another social media will not work.
If you have a good following on YouTube then your followers will be glad to know that they can also follow you on Instagram, where they can see more unique content that they would not otherwise have had access to. Also, if you start to produce merchandise for your channel then Instagram (and Facebook) can be an effective way of promoting the merchandise...so it is definitely worth the effort to build your other social media platforms. Just don't expect your new followers on one platform to immediately jump over to another one and subscribe.