I can’t speak to combo washer/dryers, but heat pump dryers have been around for several years. We got an LG one a few years ago because our old one vented into the garage and there was no practical way to extend the vent outside.
We’re very happy with it. It does take slightly longer to dry clothes, and the capacity is slightly smaller than our old electric one, but they’re also gentler on clothes. We haven’t had a single issue with it yet over the years.
Biblically-accurate Ace Combat aircraft.