Secure erase depends upon the drive firmware correctly implementing the function. The only study I've seen that actually tested this found about half of drives

Secure erase depends upon the drive firmware correctly implementing the function. The only study I've seen that actually tested this found about half of drives did not do it properly! But that was from 10 years ago now. I once used secure erase on a nvme SSD and found some of the partition table was still present when going to reformat, even though the operation indicated success. I eventually tracked it down to the drive being mistakenly mounted at the time of the secure erase. So there is your other failure mode, making sure you and your software utilities also perform the secure erase correctly.