There are no worthwhile shortcuts towards building your followers.

Yes, there are sites out there that allow you to buy thousands of followers at once. But these will ALWAYS be unauthentic. They are  quite often bots, no matter how the provider positions them. It’s a waste of money. These accounts will never interact with your profile or provide any value whatsoever. It’s also likely Instagram will flag these inactive accounts and remove them. So they will never be a longstanding follow anyway. Building your followers takes patience. Prove your credibility by being active and giving people a reason to want to follow you.

Don’t get in the mindset that people aren’t appreciating your content. Growing your followers takes time!