When a rule says that examples include A, B, and C, then the implication is that there are other activities that are not excluded, but that are not listed. Do you truly believe that a DM can only call for a check under RAW in exactly those four cases - sheer, slippery, hazards, something trying to knock you off!? If you do, then you are stepping away from the reasonable implication of the RAW. If you do not, then the list is indicative not definitive.
For example, our climber is in the grip of a tropical disease that causes their grip to be weak and uncertain. That seems to me to be a complicating factor that justifies a check, yet it isn't one of sheer, slippery, hazards, something trying to knock them off. Therefore, under your interpretation, it must be excluded.