A message log can also be visible...? The only differences between messages in toasts vs messages in a log is that toasts control the user rather than the other way around.
Isn't a toast just the tail of a message log that's visible for a few seconds after a new message is added? I don't always want the entire log to be occupying space on my screen, but I do want to see when new items get added.
The problem is that everyone implements toasts, and no one implements the message log, even though it's the latter that's more important to have.
I'm also ADHD and, like OP, I appreciate having the stream of toasts that lets me know what the software did. It's saved my butt a bunch of times when I accidentally do something I didn't mean to (deleting instead of archiving, for example). A message log would just get ignored, but toasts help a ton because they're visible.