We are talking about the same thing....
You can gain SR simply by driving around (sectors much like deltas are just a point to measure from)
You will gain more SR racing other cars closely without incident, overtakes or being overtaken without contact or side by side racing.
If it was based purely on sectors then you'd expect to get 14x more SR from the nordschlife than say the Tri Oval at Daytona?
To be clear just driving around at the back can gain you SR but it's at a slower rate than being in proximity to other cars cleanly (following, side by side, over taking, being over
taken etc)
This is why parking it in the pits can help save/or modestly gain SR vs the massive quitting penalty you get.
Edit:
From the manual
View attachment 1405509
From a 3rd party
View attachment 1405510
Both of these things can be true at the same time.
"Just driving incident free will nett SR"
"Closely racing with other cars without incident will nett SR at a faster rate"