why does the spi in microsd cards break so often?

Solution
Yes, it does. While they are 'capable' of being used in multiple different devices and moved in and out of them, it is really best not to. They are honestly not made to withstand the wear and tear.

You are better off getting a card for each device, and then when you want to switch data from say a camera or phone, etc., to a computer, connect the device (with the card still in it) to the computer to transfer data.
Yes, it does. While they are 'capable' of being used in multiple different devices and moved in and out of them, it is really best not to. They are honestly not made to withstand the wear and tear.

You are better off getting a card for each device, and then when you want to switch data from say a camera or phone, etc., to a computer, connect the device (with the card still in it) to the computer to transfer data.
 
Solution