superfast (too fast?) electric scooters

[thm_w]

You can keep pointing to data from athletes, but that does not link/match/inform data about average people. Every person is unique and has different limitations on their sustained power, the amateur trials that NASA modelled dropped 30-40% from 2hr to 4hr, 150W to 100W. Or you know instead of trying to extrapolate on highly variable human performance data, just go back to the actual question...

Its normal human physiology. The graph mostly just shifts up for athletes, taper off rate at the low end should be similar.

This one looks like it goes from about 160W to 130W from 100 to 200min: https://www.researchgate.net/figure/Reproduced-from-NASA-experimental-results-on-sustained-maximum-power-for-one-person_fig3_257434421

The key is that so long as you stay below Critical Power, your body is able to maintain a physiological steady state. After several minutes, oxygen use levels off, and lactate concentration levels off. In the muscles, the concentration of creatine phosphate (PCr), ATP, inorganic phosphate and hydrogen ion (i.e. pH, or how acidic it is inside the muscle) stabilizes.

[switchabl]

Its normal human physiology. The graph mostly just shifts up for athletes, taper off rate at the low end should be similar.

This is probably (mostly) true. However there is also a big mental component and that may explain some of the variation in the available data. To put it bluntly, in my experience, riding for 1+ hours "to exhaustion" is bloody hard and not particularly fun, less so on an ergometer, staring at a wall. Most serious athletes will be able put in a more or less consistent effort that gets close to their physiological limits. Many non-athletes will have no idea what they are physiologically capable of and may stop way short of it because they "feel" exhausted. Pointing a gun at them to provide the necessary motivation is generally frowned upon by ethics boards.

For longer periods, fueling becomes increasingly important, so results will vary more depending on carbohydrate intake during (and prior to) the test.

So IMHO the question "what power can an average person sustain for X minutes/hours" is not so easy to answer (and may not even be particularly well defined). And I agree that for practical considerations the more interesting one is probably what speeds they actually ride at.

[Someone]

You can keep pointing to data from athletes, but that does not link/match/inform data about average people. Every person is unique and has different limitations on their sustained power, the amateur trials that NASA modelled dropped 30-40% from 2hr to 4hr, 150W to 100W. Or you know instead of trying to extrapolate on highly variable human performance data, just go back to the actual question...

Its normal human physiology. The graph mostly just shifts up for athletes, taper off rate at the low end should be similar.

This one looks like it goes from about 160W to 130W from 100 to 200min: https://www.researchgate.net/figure/Reproduced-from-NASA-experimental-results-on-sustained-maximum-power-for-one-person_fig3_257434421

The key is that so long as you stay below Critical Power, your body is able to maintain a physiological steady state. After several minutes, oxygen use levels off, and lactate concentration levels off. In the muscles, the concentration of creatine phosphate (PCr), ATP, inorganic phosphate and hydrogen ion (i.e. pH, or how acidic it is inside the muscle) stabilizes.

That is one biological system that levels off, and you link to the limited version of the data I already posted (but you seem to have not looked at so I'll inline it here...)

National records and international competitions show a steady drop in the achievable sustained power. There is no steady state asymptote.

[thm_w]

Its normal human physiology. The graph mostly just shifts up for athletes, taper off rate at the low end should be similar.

This is probably (mostly) true. However there is also a big mental component and that may explain some of the variation in the available data. To put it bluntly, in my experience, riding for 1+ hours "to exhaustion" is bloody hard and not particularly fun, less so on an ergometer, staring at a wall. Most serious athletes will be able put in a more or less consistent effort that gets close to their physiological limits. Many non-athletes will have no idea what they are physiologically capable of and may stop way short of it because they "feel" exhausted. Pointing a gun at them to provide the necessary motivation is generally frowned upon by ethics boards.

For longer periods, fueling becomes increasingly important, so results will vary more depending on carbohydrate intake during (and prior to) the test.

So IMHO the question "what power can an average person sustain for X minutes/hours" is not so easy to answer (and may not even be particularly well defined). And I agree that for practical considerations the more interesting one is probably what speeds they actually ride at.

Yeah true.
Here is one listing 12-26km/h but does include a few ebikes as well as uphill/downhill sections: https://pubmed.ncbi.nlm.nih.gov/31560212/

Sweden, but the limit is 25km/h so doesn't tell you much about higher speeds:

A traffic safety concern regarding EAB is that the higher average speeds and the higher mass’ of EABs could lead to increased injury severity. However, when comparing injury severity for EAB cyclists with that of other cyclists in this present study no significant differences were found.

https://www.sciencedirect.com/science/article/pii/S0001457521005418