Ryzen still doesn't have Thunderbolt. For some -- like me -- this still excludes Ryzen.
And you are right that Intel U chips are rarely are shipping with 90Wh+ . But https://www.asus.com/Laptops/For-Home/Zenbook/Zenbook-Flip-1... does. The Lenovo Yoga 7i 14 (Yoga Slim 7) has a 71 Wh, the Schenker Via 14 has a 73 Wh, the HP Spectre x360 15 72.9 Wh, the MSI Summit E15 has a 82 Wh.
Thunderbolt is Intel's proprietary technology, I don't think AMD will ever have that. I think you'll have to wait for USB-4 if the current speeds really aren't enough.
Oh of course, I didn't want to go into that detail but trust me I know all that, TB3 got donated to USB IF, it became USB 4 with a few extras (most importantly the USB packets on the bus). And then Intel took USB 4 and put a marketing name on "USB 4 with every optional feature on" and called it Thunderbolt 4.
And yes, likely next year, AMD will have USB 4 but -- not right now.
And the problem is not exactly the bus speed -- although 10Gpbs is not that much -- but the lack of external PCI Express (or any other DMA capable protocol but the last non-PCIe tech doing that was Firewire and that's gone).
Not necessarily so, ASUS as an example has released an AMD board equipped with thunderbolt 4 in the form of the B550 ProArt. In a laptop it’s perhaps a bit more problematic until USB-4 comes along in greater volumes, but by then Thunderbolt and USB-4 will be the same thing
Because OEMs would give their left nut to sell to Apple, and that just isn't true of, say, Dell or Asus. Intel lost Apple as a customer for their CPUs, but they would bend or break the rules to license Thunderbolt to Apple even without an Intel CPU... because Apple is Apple, the company that invented personal computing and that has been the driver of every revolution in the industry since.
And you are right that Intel U chips are rarely are shipping with 90Wh+ . But https://www.asus.com/Laptops/For-Home/Zenbook/Zenbook-Flip-1... does. The Lenovo Yoga 7i 14 (Yoga Slim 7) has a 71 Wh, the Schenker Via 14 has a 73 Wh, the HP Spectre x360 15 72.9 Wh, the MSI Summit E15 has a 82 Wh.