SDcardholder.com makes a variety of card holders, including a perfect one for MicroSD. Each card is about the size of a credit card and can hold 10 MicroSD cards and one SD card adapter.
I grabbed one in green, blue and red, then bound them together with a bent paperclip.
Now when I travel and have finished a card, it goes into the red holder until I can download it to an external drive. Once ready for formatting, it goes into the blue holder until I have time to sit and format a number of cards at once. Lastly, when formatted it goes into the green holder.
The MicroSD card holders have a little tab to hold in your cards and that means it does take two hands, typically, to remove the card. But it makes them more secure.
You can buy them in a variety of colors: https://amzn.to/3vqLEMl