As a counter- I’ve ridden a few different direct drive trainers over the years but none have made me sway away from my Kickr Snap wheel-on. The tyre doesn’t slip if it’s tensioned correctly and I believe the flywheel power measuring system was ultimately added to the direct drive kickrs because it works so well. (I think the early ones had a strain gauge 🤔).
The reason I say that is inertia! Even a really heavy flywheel doesn’t have as much inertia as an equally heavy flywheel + an entire wheel spinning around!
The ‘road feel’ if you like: just feels that bit nicer to me.
I think many direct drives are quieter now, and of course you don’t have to have a trainer wheel/tyre setup or check tyre pressures before a ride. And loads of other people love the road feel of their chosen DD brand.
But I don’t feel like I’m missing out on anything with mine.