My view is I’m against banning them.
If we’re going to ban them we should also then ban mile upon mile of dual carriageway roads that are also 70mph, don’t have a hard shoulder nor have refuge areas and are often less monitored with less gantry information. Think large swathes of the A1 or A14 as examples among may others.
Also are we talking “all lane running” or actual “smart motorways” because theres a difference which often gets forgotten.
What I’m in favour of is improving technology/infrastructure to reduce risks and increase awareness of issues/reduce speed of response.