FB complained about lost revenue from Apple locking down tracking so if $X is what they make per user via the official app store and $Y is what they make on the sideloading app store then there exists $Y-$X = $Z where $Z (or even $Z * some number) can be used for "customer acquisition" to convince people to switch with the goal of making more off them in the long run.

"Get $5 in FB Credit if you download this app", "Get access to this cool new filter if you install this app", etc. No, people here on HN won't be swayed by that but a good number of people will.

That means you that if a vendor does something particularly egregious, stuff akin to malware, they can pull the certificate for that vendor. They don’t do that often: IIRC, they’ve only done that in macOS a handful of times.