Toothbrush UX is the same today as it was when we were hunter gatherers: use an abrasive tool to ablate plaque from the teeth and gums without removing enamel
As somebody who's tried using a miswak [0] teeth-cleaning twig out of curiosity, I can say with confidence it's not the same experience as using a modern toothbrush. It's capable of cleaning your teeth effectively, but it's slower and more difficult than a modern toothbrush. The angle of the bristles makes a huge difference. When the bristles face forward like with a teeth-cleaning twig your lips get in the the way a lot more. Sideways bristles are easier to use.
That’s just not what user experience means, two products having the same start and end state doesn’t mean the user experience is the same. Imagine two tools, one a CLI and one a GUI, which both let you do the same thing. Would you say that they by definition have the same user experience?
If you drew both brushing processes as a UML diagram the variance would be trivial
Now compare that variance to the variance options given with machine and computing UX options
you’ll see clearly that one (toothbrushing) is less than one stdev different in steps and components for the median use case and one (computing) is nearly infinite variance (no stable stdev) between median use case steps and components.
The fact that the latter state space manifold is available but the action space is constrained inside a local minima is an indictment on the capacity for action space traversal by humans.
This is reflected again with what is a point action space (physically ablate plaque with abrasive) in the possible state space of teeth cleaning for example: chemical only/non ablative, replace teeth entirely every month, remove teeth and eat paste, etc…
So yes I collapsed that complexity into calling it “UX” which classically can be described via UML
I would almost define "experience" as that which can't be described by UML.
Ask any person to go and find a stick and use it to brush their teeth, and then ask if that "experience" was the same as using their toothbrush. Invoking UML is absurd.
On the positive side, my electronic toothbrush allows me to avoid excessive pressure via real-time green/red light.
On the negative side, it guilt trips me with a sad face emoji any time my brushing time is under 2 minutes.