2014-2018 was prime Leveon Bell years with Antonio Brown. Prior to that was a 2 year lull, but before that they squeezed 2 productive 1100+ years out of Mendenhall and before that they had Willie Parker.
The Bills haven't had a 1,000 yard RB or a rushing attack they could rely on since Shady back in 2017. This is a problem and it will rear its head, yet again, when the weather gets bad.
Ben was tough as nails and an outlier for QBs historically. He shouldn't be used as the norm. Most QBs take less of beating than he and don't last as long.