Here's the deal...Facebook is a business. Sure, they like to make it look like they are social and free, but ultimately they are bringing in $16 Billion a quarter in revenue.

And to protect the integrity of their business, they want to keep users on their platform. Hence why they now have Facebook watch, IGTV, stories, etc.

So when you post a link in your posts that takes someone off of the platform, and when you do that, they don't support that; meaning they won't show your content as much.

and if you use a link shortener, the views will go down even further.

So what about link shorteners?

If you are using paid advertising, you can use them.

If you aren't using paid advertising, I would avoid them because Facebook will hide your content (mostly) anyways.