Thanks @A.B for sharing the information, so write cycles depends as well on the type of NAND flash storage used in the card.

Oh I see, thanks @harrymc, so the key factor is the wear-leveling technique, a must have to SD card choice when longer life span is of utmost concern. I found this Kingston Industrial microSD which has the wear-leveling feature kingston.com/datasheets/sdcit2_us.pdf, I'll try this out as WD Purple microSD is not available online in our area.

Thanks @RomeoNinov for sharing your thoughts in answering my question. Given that intensive write operations, if ever it achieves to 100K write cycles, do you think SD is soon to fail or experience wear? For example an SD card is around 64GB capacity and it only achieved 5GB of written data, do you think it will also soon experience wear or fail if this 5GB already reached the 100K write cycle? Even there is ample of space to be written?

Your answer make sense to me, I will try. Thanks for the details @Vladimir Botka!