Some of these surprise me - or used to. Freshford, whilst it has a bridge, has an adjacent level crossing and ramps / flat onto both platforms, for example. Also scratch my head (but perhaps others can tell me) about places like Sea Mills.
What is really disappointing from a passenger viewpoint is the grey circles at stations that GWR▸ serve but don't operate ... I'm sure that passengers who need accessibility would prefer to be told "yes/no/partial" rather than "not ours" - passengers don't mind who operates a station, but they do care if they can get on and off a train there!
Sea Mills has no steps ,but a reasonable amount of slope from the platform to the entrance gate ,no way that could be described as level ...