"Other than that single feature (generating RealTracks) they are hard-pressed to give a reason to use RB! "

Not really hard-pressed at all. For instance;

You can enter chord progressions the same as BIAB
It works extremely well with midi
and it has thousands of midi styles
midi styles and be replaced with RealTracks and Real Styles
It has access to thousands of Real Styles (different from RealTracks)
It works with User Tracks
It's integration with the new Stylemaker
The Multiriff generation feature - it is uniquely different from generation and regeneration
It's integration with the Audio Chord Wizard
The new 2016 feature 'Record a click track'
The Karaoke lyrics window and the .kar format
The ability to save .XML files
The guitar tab window
The piano window
The notation window
The performance artists files
Some of the above features are geared toward teaching or learning to play an instrument, composing and are bypassed by those who use RB for backing tracks or songwriting and arranging.

RealBand is not a one trick pony that it's only unique feature is RealTrack generation. Real Styles and Midi styles are valuable resources in of themselves. No other DAW can integrate with BIAB, RealTracks, midi styles, RealStyles and midi styles the Way RB can.

BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.