Here even the grocery stores take checks (not that I use them unless forced to, so I end up writing three or four cheques a year). For Tesla I guess it's a balance between the cost of writing a cheque and the cost of verifying the direct deposit bank account number plus the cost of returning or abandoning the funds if someone makes a typo. With a cheque you only have to get the name and amount correct.When Tesla owes money to a client they still use physical checks sent by US mail. Physical checks, for those who don't remember, are pieces of paper (a processed wood product) sent by an antiquated method once common that employs 'internal combustion engines' (look that up) topper vehicles that move that 'mail' from point of origin to small boxes that each person(s) have to access physically. Those then are transmitted the recipient's bank, luckily that normally can be done electronically. Tesla gets 'float' out of that. I'm still waiting for my 'check' for funds tesla owes me from my February purchase of a Model Y.
The last check I had before that was some years ago. In Brasil we do not even have check for our accounts. Every payment, even for pennies is electronic now.
I'm surprised Tesla gains enough float to justify all those paper processes.