It takes a bit of effort even to get an app on public TestFlight on Apple’s side. Plus the fee, which is reasonable for a thorough review.
Anyways, I edited my comment to not misrepresent the Play Store process, thanks.
Our app gets held up fairly regularly, I'm not sure why us in particular, but we have an app that requires our licensed service to use, quite often they'll muck up the registration process with the test accounts we provide (they're one-time) registration, and then hold up our app until we provide more test accounts for them to use.
They also recently took issue with some functionality of our app that they claim existed (but doesn't) and forced us to update our privacy policy to mention it so we can get it through. I know for a fact, said functionality doesn't exist, because I lead the team that builds the backend, but there was just no arguing with them.
It's even more fun when it's a purely administrative thing like updating information in a link on your developer profile, but they make you upload a near identical binary, since the automation has kicked in again and they can't rereview an already submitted and rejected app.