Unfortunately there's already steganography detecting software on the market[0], and it seems they have a branch in China[1]. But that is a little reductionist of me because there are evolving techniques being produced by researchers that are not so easy to detect. For example I recently read about a CNN-based method for hiding data in images that proved much more resilient against detection.

[0] https://www.wetstonetech.com/products/stegohunt/

[1] https://www.wetstonetech.com/corporate/channel-partners/