The author talks about the problem with using hardware keys, but they neglect to mention that many websites and apps simply do not allow the use of hardware key

The author talks about the problem with using hardware keys, but they neglect to mention that many websites and apps simply do not allow the use of hardware keys! They will insist you use Apple or Google syncable keys. So after you have spent the money to buy 2 or 3 hardware keys, you find that they are not accepted.