Fwiw Alpine Linux is very easy to set up in diskless mode. That's what I used for my first Pi 4 install. It does boot up and load packages from the sd card, but after that everything runs from RAM.

Check out the high endurance SD cards they typically support 10 to 100 times the writes other SD cards do and aren't that much more expensive. They are most often used in dashcams and the like.

Or for a kiosk you could probably run exclusively from RAM and never touch the SD card after the initial boot.

We found that booting from USB and using a 2.5" SSD drive is durable.

If this works for you: I've found that it's good practice to mount root as read-only once your software configuration is stable, and try to use tmpfs for everything.

3 years for SD card is very long. Mine requires SD card replacement after 3-4 months. I hate that storage medium.

Add something like this to your /etc/fstab. Will save a few touches to the SD card and enhance system security a little. My last SD went for 3+ years on a decently busy little Pi.

  ##
  ## Decrease touches to root partition a little with noatime flag
  ##
  /dev/mmcblk<NUM>p<NUM>  /               ext4    defaults,noatime  0       1


  ##
  ## decrease writes because tmp activity by mounting as tmpfs
  ##
  tmpfs /tmp tmpfs ddefaults,nodev,nosuid,noexec,noatime,mode=1777 0 0


  ##
  ## /dev/shm security measure
  ##
  tmpfs /dev/shm tmpfs defaults,noexec,nodev,nosuid 0 0

Try disabling syslog and swap.