Impractical is a word I prefer. The reason it is impractical is firstly it is lossy not lossless data storage meaning that when your fingerprint is scanned a whole ton of information is discarded immediately and then the fingerprint is normalised which discards yet more still before being stored.
So the resulting data stored literally doesn't contain the same level of information as a "real" human fingerprint, and as a result of that the data might be useful in recreating a simulated fingerprint which can beat Apple's TouchID but it would likely still be incompatible with most other fingerprint systems and databases, and the fingerprint you recreated from the data likely wouldn't look like your "real" fingerprint as several million different fingerprints can result in the same lossy compressed representation stored in the phone.
Imagine it like taking a photograph and then using a JPG compressor to decrease that photograph's size by 80% an then trying to get back the original photograph from the compressed JPG. While you can certainly get close it is implausible that you'd ever get the original image back and even if you did get it back there is no way to verify that the "original" you recreated was the same as the actual original without the actual original to compare it to.