It's kind of like saying, "I've never considered getting a job because the risk is too big that a faceless corporation is going lay you off without any reason and visibility."
The analogy would be more accurate if you could end up in a worse off position by taking the job / making the app, say through lost development time with no payoff
The risk of your app being banned when there is only 2 marketplaces is way way higher than the risk of being laid off when there are many more companies.
IMO OPs argument breaks when they equate a bit of risk to a lot of risk, as if any risk amount were the same as any other.
Being controlled by software restricts choice, while being wiped out by software eliminates choice altogether.
So something may be an existential risk to this company or this endeavour. Only a small fraction of usage of existential risk are globally scoped to humanity.