It's not the chord structure that's repetitive (that's up to YOU)... It's what the arranger DOES with the chords that's repetitive.
You hold a C chord down for two bars (maybe four if it's a good style!), then hold down an F chord... Does the arranger play anything different? NO! It's EXACTLY the same pattern, transposed. Maybe small differences if the chord puts a part or two outside it's assigned range, but it won't be a different line, just a weird jump as say the bassline tries to avoid going too low.
Now, rinse and repeat for minor chords, seventh chords, and maybe diminished, and that's IT. For that variation, you've heard it all...
That's why, other than the occasional Weather Channel tune, you don't hear arrangers on the charts (at least in arranger mode). Real players put in subtle differences every time they play something, intentional or not! Bass players lead the chords, and walk TOWARDS a change, not follow it.. Guitar players and keyboard players use voice leading and chord inversion changes on change transitions.
As good as arrangers have got, they still don't have the technology to recreate the complexity of real players. And the few arrangers that DID offer LOTS of variation, depending on chord type, velocity, speed of notes in the right hand, etc., (some older Korg's, for instance) withered on the vine, mostly, I would imagine, from the reluctance of style composers to essentially have ten times the load to create a good style.
The integration of Guitar Mode on Korg's into the arranger engine is a good start. If it works like Roland's Guitar Mode, the inversion of the chord depends on what area of the chord recognition section you play in, so changing chords by not moving your hand, just playing an inversion does the same thing to the guitar part. Applying that kind of technology to piano and string and horn parts, etc., may start to improve things, but there is no getting away from the fact that no-one KNOWS what the next chord will be until you play it, so walking TOWARDS a change never happens, and voice leading on single lines (although implemented in Roland arrangers to a certain extent) is haphazard, at best.
As lively as any other method of conveying a tune? Not as good as a good real band, yet, IMO...
_________________________
An arranger is just a tool. What matters is what you build with it..!