Happy to help! There’s plenty of other options too (e.g., SSD) as folks mentioned, but this works well out of the box with no additional hardware. SD has been absolutely fine for my use (Pi-Hole), while still requiring maximum uptime so the family doesn’t riot if the internet is out.

Another option is to use Image File Utilities on the Pi to create an image backup. You can use cron + a bash script to create incremental backups using the tool (e.g., take a ‘fresh’ backup each month, with daily incremental backups in between). I mount a network ‘backup’ drive (a local NAS, but you could use anything) to save the image to so I can actually access it. Then, just use balena etcher to flash the backup iso in the event of a failure.

• Here’s Image File Utilities: https://forums.raspberrypi.com/viewtopic.php?t=332000
• And a backup script + cron entry: https://forums.raspberrypi.com/viewtopic.php?p=2199452&hilit=cron#p2199452