Yes, I understood. But I too find that "a sports watch without lap function is somehow ridiculous", even though I can't recall when I've last ran around in circles on artificial tracks.
(Actually, I find it a little confusing that they still call the button "Lap", even though starting a new interval or progressing to the next workout step are probably the more common uses.)
Well I am not sure what I would get from the data if I devided it that way : / I guess I'm just a dumb runner ("Run, Forrest, run" : ) type. I just run from the start to finish. And all around my house are hills, so usually I just get up, get dressed and run uphill without any food or drink, warm up... Hello lactate : )
If you really want to say that every run with the use of a lap buttons is ridiculous, why to you use a sophisticated sports watch?
Maybe you have never heard it, but interval training makes fun, makes you faster, can happen anywhere and also some hard pace work on a track can be a nice thing.
Additionally the lap function can simply be used to measure distances, e.g. the lap around your favorite lake, how many meters of height your favorite climb has etc..