I think this is a misunderstanding Stefan. No one wants to tell anyone how much motor support he/she has to use or what ebike to ride. I/"we" only say, that ebikes with assist drives like SL are so light and ride almost like a normal bike, that you can even benefit from them/more than from a acoustic bike, if you use only little or once in a while motor support. Of course one can use more and all the time motor support for whatever reason, then the benefit frome the ebike is even greater.Probably in your state of health. I could ride the SL without assistance only for a few km, in emergency. (Check Jodi what "angioplasty" stands for).
And I had to ride my "big" Vado unpowered for 15 km once. It was an ordeal.
But you said (as far as I understood you), that one has no benefits riding a light (SL) ebike if he/she does not use much motor support and that's not true. These light ebikes close the bridge to normal bikes and therefore it needs less use of the motor then normal ebikes and you already benefit, can ride longer and more interesting tours, etc.
If 15km without motor is a torture for you with the big a Vado (it is as well for me with the Stromer...), then a smiliar torture with the lighter Vado SL would be maybe 25km and with an even lighter normal acoustic bike maybe 30km.