I don't think it will. Android and the Play Store have shown that even with the ability to install arbitrary apps and stores very few apps that would have been available on the Play Store have migrated to only be available on other stores.

So the tradeoff is a fairly large number of previously disallowed apps are now available, if you want. And a small number of previously allowed apps are only available outside of Apple's store.

Of course if this is worth it to you depends on how much you value either side of the equation but at least in the Android case it is a clear win to me.