Presumably that's because relational data is much easier to work with when you aren't using ML, so most companies have a lot of pre-existing data to work with a

Presumably that's because relational data is much easier to work with when you aren't using ML, so most companies have a lot of pre-existing data to work with and can jump right in and start using ML without collecting a lot of new data. Image ML will take much longer to catch on because companies haven't historically had much of a reason to collect image data in quantities that are too large for humans to deal with manually, so they are pretty much starting from scratch when it comes to data collection.