The trick with Everesting seems to be to find a hill that isn’t too steep (otherwise you’ll really struggle later on), isn’t too shallow (you’ll need to ride for much further distance to get the altitude gain) and is reasonably varied in gradient to be able to work different bits of muscle and to mentally split it into sections.
Most hills/Strava segments that get Everested seem to have between 150 & 250 metres of ascent to reduce the number of time you need to climb them. Bigger or longer climbs might mean fewer ascents but increase the likelyhood of getting too cold on the descents.
Then there’s traffic – it wouldn’t be much fun Everesting Winnants Pass or Malham Cove road on a summer weekend.