If your profile will be popular you will be able to earn on advertising, but it is not so simple to find good sponsor nowadays.
It is simple to find sponsors, actually they'll come to you unexpectedly. What you need to work on is your reach and community.
Without such, even if you find good sponsors and propose to them, they still have to consider those two. But if you've got those two and its vast, they'll be the one to contact you first.
I agree it's not that hard to find sponsors these days. Moreover, many large companies know the great effect of social media to promote their
products. So if we have a lot of followers on Instagram and are always active in creating content, many sponsors will come to us. So just focus
on creating interesting and useful content, so that many people follow our Instagram. That way sponsors will come by themselves, therefore
being an influencer on social media is in great demand by many people today.