I remember first entering Proud's sump flats, using an Aluminium ladder left over from Wilson's mine tours.
We took it out of Carr's, nobody moaned about the effort required, but relatively, Ally ladders were expensive pieces of kit, so to use an abandoned, one was a bonus!
Nowadays collapsible Ally ladders can easily be taken to lots of places so surely putting in fixed ladders must only take place where it is absolutely necessary.
The obvious place that comes to mind is the sump from Smallcleugh random into Capelcleugh , where some the calcite ladders are showing their age.