That’s because it’s bullshit 
So that’s it then, you say so, so it must be true.
I’ve had several arrangements with different women with no financial outlay save for the dinner and hotel. I’ve had trips away, all expenses on me of course but no further payment. I am also 60+ and have had no problems with attracting younger women, I currently juggle a 22 year old, two 27 year olds and a 43 year old.
Whilst with most of my arrangements there is a financial outlay, of course, I never go above £300 for an all day ‘day room’ or an overnight. I use SA and SB primarily with a Tinder dabble every now and then. I’ve had a few one off dates but most are repeats as I wouldn’t go away with someone I wasn’t completely comfortable with. There’s a lot more time spent sightseeing and eating than shagging and you have to be compatible.
So it’s not necessarily cheap but it’s two people having fun together. I get the feeling from this particular thread that some guys treat arrangement dates as seeing an escort but for a little longer than usual. That’s fine, each to their own, but if that’s what you seek that’s what you’ll find.