As of now this seems to be the best bet of uploading multiple images at once.
Basically, Glide does not allow uploading multiple images at once using the image picker, so you must configure a web yourself to do so. Once you get the input from the users, it’s your choice to store them on Cloudinary, or add a button that might trigger a webhook to Integromat/Make or Zapier to upload those files to Google Drive.
It’s quite complex, though. I wish we have the ability to do so using the native image picker.