SD cards withstand a large number of write cycles and the control logic automatically spreads out the data usage so if you consistently write around 10 gigs of data to a 64 gig card you won't be using the same 10 gigs of storage locations each time. I believe the industry mean standard for standard quality SD cards (regardless of transfer rate or other parameters) is around 100K write cycles but that doesn't mean that every card will make that number or fail at that number but it does mean the card has a very long life in normal service and you are likely to lose the card or damage the contacts before it dies. Newer SSD drives have far greater write cycle capability and provide a "health" report through smart technology but they are a different animal with much a much higher duty cycle in typical use.
I would take a good look at the card contacts under a magnifier to check for damage, "dirt", or wear and you can run chkdsk on a SD card in a PC just like you would a physical drive.
Unless you are using the SD card for a lot of different devices, the shutter in your DSLR should wear out well before the SD card memory due to high duty cycle. They certainly do wear and that is one reason you NEVER want to have the system running defragmentation or other similar operations on a SSD because it isn't needed and needlessly shortens life. I have never checked to see what is done during a fast full format of a SD or CF card but I suspect the wear is no greater than simply erasing the files. I erase files after transfer and format the card in camera every couple of weeks during heavy usage.
Rodger
EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video
