Facebook Ads vs. Influencer Marketing (IG posts)?

What have your experiences been?

I've been playing around with Facebook ads while my social/dating app is in beta testing. It's not officially on the iOS App Store yet, so while I'd really like to optimize for App Installs, it seems the best thing I can do for now is target for Landing Page Views. Then hope they'll install TestFlight just to be able to download my app lol.

In my experimentation, I've paid about $2k, for about 9k clicking the ads and viewing my landing page, which converted to 1k App Installs through TestFlight.

That's kinda shitty, so I'm really hoping it'll get better once:

My app is actually released so users don't have to go to my landing page, install TestFlight, then go back and click a button to download the app => the ad would instead take them straight to the store for App Install

People actually start buying stuff so I can create Lookalike Audiences for spenders like them/customer lifetime value and target for what really matters: App Purchases (right now there are only fake beta test purchases and people seem to like those probably mostly because well... they're free haha)

Then I'm also curious how just paying someone to just post on Instagram would do because I'd imagine it'd actually do better. I'm trying to find someone right now just awkwardly DMing people, so was also wondering if y'all use any tools to for influencer marketing management like that?

Would love to hear about what worked for you and what didn't. Thanks!