you don't absolutely have to use a microSD, you can use it just fine via an USB, there are just tradeoffs to using it through USB
Discussion
Their website says I need a microSD to receive bitcoin at the address I generated. Is that not true? I’m so confused.
#[4] considered shipping simpler new product
You would want the micro USB at least for importing the cold card “wallet” into your software wallet (such as Sparrow if in a desktop) Receiving bitcoin would be 100% managed by the software wallet and would not require the cold card (it would only need the micro SD and CC for sending the bitcoin)