I think the point is that the cost should not be the main motivator. I would agree that there needs to be other differentiators in addition to cost, which could provide sufficient moat against other competitors, big or small.
It's possible that there could be non-obvious innovations in how to save money with a low reliability threshold, which Amazon might not be able to effortlessly copy.
It's... interesting... that Amazon offers reasonably priced bandwidth on Lightsail, but it's against the TOS to use it in connection with other services.
Putting it into normal S3 only costs $2.50 a TB. That's very affordable.
To get out of Amazon entirely, they definitely want to gouge you, but it's not the end of the world. If $24 a year is an acceptable storage price, then Snowball export costing somewhere around $36/TB in bulk isn't too awful. (And if you don't have enough data to fill up a snowball, you can probably smuggle it out through lightsail.)