They are free to return their phone and buy one that meets their needs.

They were wrong in their supposition. It's part of free market process, asymmetric information.

The only regulation we need here is a right-to-repair law, that requires hardware manufacturers to provide users root access to any firmware or software flashed onto the device.

Or maybe you think that if Apple went out of business, or simply decided to shut down the App Store tomorrow, then all the users with bricked devices should have no legal recourse.