To run an operating system off a SD or MicroSD card it’s recommended to not go beyond 40-60% of max capacity, it’s best to format / partition the card with this restriction in mind…
or otherwise restrict space usage.
60% is the endurance and best capacity configuration
30-40% is the performance / endurance configuration
A quality brand endurance model SD card , by quality brands i mean such as Samsung or Sandisk and i’m sure many other leading/top memory manufactures.
Going beyond the 60% capacity mark on an high activity use of an SD card or similar compact flash cards will in most cases result in the card wearing itself out and the data may be lost.
The reasons for this is explain in this thread.
heat can ofc also destroy or damage the cards, as with most other electronics…
SD cards will inherently have less endurance than an SSD, so do keep backup’s of important data.