If you think all there is to using an arranger is holding down a chord and push buttons you are really in the dark. Too much for me to explain if you really think that, which I'm sure you don't.

As far as the cheap/greedy/lazy thing, if you are a hobbiest that may be true, but if you're supporting a family as an entertainer, the odds are WAY against doing that with a "real band".
I tired years ago of teaching songs to three or four other people, then having to replace them, referee arguments among them, provide equipment for them, transport it, set it up, repair it when it breaks, etc., then hearing them gripe because they weren't making enough money.
Now I don't worry that the guitar player must tune up before every song, that the drummer might run off with the bass player's wife, that the one "singer" is jealous because the other got to sing an extra song--and that just scratches the surface of band problems.
Most all of the cheap/greedy/lazy pickers I've known are sidemen in bands.
For every decent band I've heard there must be 1,000 very bad ones. But that's o.k. if you are just having fun. I think that's why I've been working steady for 30 years while the only "real band" I can think of right away that has done that is the Rolling Stones. (Seriously I know there are others, but that doesn't support my argument.)
A couple of weeks ago I booked a job and they insisted that I have a four-piece group. I hired a wonderful sax player, a world-class guitar player and a truly professional piano player. All I did was set up the p.a., pick the songs, play the chords generating bass and drums and fill in on exotic sounds such as harmonica, pedal steel, vocal oohs and aahs, etc., and sing. Yes it was fun to work with these pros!
By the way, I paid them $100. each and I made $800. Bring on the new arranger keyboards!
Not much to do here but watch Rita dwindle down and rant and rave!
DonM