Hydrolic brake

[Ajax Bay]

Can't help but notice that there is a large potential braking surface running all the way around the wheel, just below the tyre. Maybe that could be used for a more reliable technical solution?

Where did you "notice" this? Any braking surface the rims might or might not have is not in the images shared in the OP. You are employing a vivid imagination: never a basis for a reliable technical solution, especially skewed by Luddite bias.
[Mixed stable here]
You're welcome

 

[Drago]

It's not as if the current technical solution was reliable though.

We all put up with different degrees of unreliability/ ease of repairm and where we plot our favoured point on the graph is a matter of personal preference, notmof absolute right or wrongness (new word (c) Drago Industries 2023)