The flash controller in an SD card is a very sophisticated device with a powerful micro-controller. It doesn't work in the simple way you describe.
The same block is not rewritten. The SD card's flash controller maintains a pool of erased blocks. when you write a block of data it uses an new block.
The Mac is not a PC so it is not that good at FAT file systems with MBR partition tables.
I wrote SdFat, the base library for SD.h and get a lot of e-mail about problems the Mac causes. Once an SD is formatted GPT, even a PC won't restore it to MBR.
That is why I wrote the SdFat SdFormat program. So you can recover a GPT formatted SD.
There are other problems with OS format utilities. Flash in SD cards have very large, 128KB or more, erase groups so file structures should be aligned on these for best performance. PC and MAC generic format utilities don't do this.
Here is a quote from the SD Assoication:
The SD Formatter was created specifically for memory cards using the SD/SDHC/SDXC standards. It is strongly recommended to use the SD Formatter instead of formatting utilities provided with operating systems that format various types of storage media. Using generic formatting utilities may result in less than optimal performance for your memory cards.