In reply to Dorchester: As others have said, approach shoes have now come on in leaps and bounds over the last few years. Some are just crazy light like my Evolv Cruzer and plenty of others cope equally well with long mountain approaches and technical climbing.
I regularly second pitches up to HVS in my approach shoes despite my rock shoes being comfortable enough. I'd even go as far as to say they would now be my default option for any easy multi-pitch.
You now either have a single solution for both the route and the climb or approach shoes that are so light that there is absolutely no need to ever consider walking off in rock shoes.
As such there isn't really any gap in the market. The market has just moved on, as it has done repeatedly over the decades.