Replacing a counterbalance spring means working above head height with winding bars, releasing and then setting stored energy in a controlled way. It is not a job that tolerates an unstable ladder or an awkward stance, which is why the ground in front of the door genuinely matters.
A significant number of Mudgeeraba driveways slope, some steeply. Where the fall runs towards the garage there may be very little level ground at the opening; where it runs away, a ladder set outside the door can be difficult to foot safely. Saying so on the call lets a provider bring the right access equipment rather than improvising.