You’re right that Glide doesn’t let you compare a Row ID directly against a “Multiple Texts” column unless you first turn that column into a Joined List. That’s because Multiple Texts is actually an array, and Glide can only do “is included in” checks with plain text. Don’t Mind it..
There is a reason — it has to do with how this data is stored in the back-end. I don’t think you can use “is included in” when looking at a certain type of data due to the way it’s actually stored (it’s not seen as a piece of text that can be broken into parts).