defragment would introduce more write operations on a system with limited amount of write operations.

Not necessary. In fact as Qbix wrote, it will do more harm.

The flash memory controller keeps a "scorecard" of how often each memory-block has been written to and tries to even-out the number of writes by constantly re-allocating blocks on writes.

Thanks for the information. Somehow I guessed that. Now, we need someone to create a more reliable way of storing data.

Punch cards - still readable after +50 years. 😀

Yeah! 😵