Again it depends on the venue. Yes you can use an Arranger with very simple backing or full out. It can be very versatile but I still think a real Piano has a more immediate connection with people and again in the right situation.
Even Uncle Daves fake piano setup will connect better than a keyboard on a portable stand. Look at Elton John and many other using digital keyboards in piano cases. But unlike us they have roadies to s help,their stuff.