https://kb.sandisk.com/app/warranty https://kb.sandisk.com/app/warranty I tried a couple of FAT32 formatted 16GB SanDisk microSD that have a "Lifetime" warrant

https://kb.sandisk.com/app/warranty https://kb.sandisk.com/app/warranty I tried a couple of FAT32 formatted 16GB SanDisk microSD that have a "Lifetime" warranty in an OpenWRT-based router that has a microSD card slot. I managed put them both into unrecoverable "read-only" mode by letting some daemon write to them unconditionally. They were purchased from a large electronics retailer not Amazon. I normally do not use SD cards or USB sticks for non-interactive, frequent writes. I usually write to them manually (i.e., interactively), either storing files or dd'ing bootable images. For example, I am not one of those people who tries to use an SD card as a substitute for a HDD in an RPi. I only use tmpfs for non-interactive writes. Is there any reason I should not conclude that these cards are not suitable for high frequency and high volume of writes.