Are you using iMovie, Final Cut Pro or some other video editor? If so, can that software see that the camera is connected an be able to import the footage?
What I have done for all my video work over recent years (from Vixia camcorders like the HF G20 through the EOS C70) is use a card reader instead.
To clarify, do you have a Mac Pro (tower) or a MacBook Pro (laptop)? Many MacBook Pros would have built-in SD card readers.
07/31/2023: New firmware updates are available.
05/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
04/20/2023: New firmware version 1.4.1 is available for EOS R3
03/30/2023: New firmware updates are available.
2/07/2023: New product announcements!EOS R8 EOS R50RF-S55-210mm F5-7.1 IS STMRF24-50mm F4.5-6.3 IS STMRF15-30mm F4.5-6.3 IS STM