Lenovo expands its ThinkPad X1-series with the X1 Titanium Yoga, an expensive business convertible. It is just 11.5 mm thin and also the thinnest ThinkPad so far, but you have to make compromises.
https://www.notebookcheck.net/The-Lenovo-ThinkPad-X1-Titanium-Yoga-is-too-thin.531416.0.html
I think more premium 2-in-1s should move towards detachable design, similar to Surface Book and Porsche Design laptops.
Thinner and lighter the most ergonomic Tablet portion, more power(possibly dGPU) and battery in the docking part, more room for better speakers, keyboard and microphone in the bottom half, and the convenience and quality justifies the high price tag.
Separating the tablet and laptop element might help resolve many issues and compromises we see here with the Yoga.
It'll be more expensive than traditional convertibles, but it's far better than trying to make existing convertibles thinner and lighter at the expense of diminishing returns.