Big tags bury you
Huge tags get thousands of new posts a minute, so yours is pushed out of view almost instantly. Smaller, specific tags move slowly. Your post stays near the top for hours, in front of people who chose to follow that exact topic.
Caption or comment?
Either works fine. Relevance matters far more than placement. Instagram uses hashtags to work out what a post is about, so a short list that fits beats a long list that wanders.
Give it a push
Tags help people discover the post. Early likes help Instagram decide to keep showing it. Try a free batch of likes right after you publish.