IMO, the footway has been lowered to meet the level of the carriageway, it's just that in this case it's been achieved by placing three steps. OK, not the gently sloping type we're used to seeing, but the criterion is an objective test of whether the footway has been lowered and the answer must be yes IMO.
So you move on to ..for what purpose? And we're missing half the available info!
The test:
..for the purpose of assisting pedestrians crossing the carriageway,
What we can see would enable pedestrians, or at least the able-bodied of them, to leave the carriageway and reach the footway. But this is not the test. It has long been held that in order to meet this standard there must be a means by which pedestrians can enter or leave the carriageway opposite i.e. they are provided in pairs, not singly. Otherwise 'assisting crossing the carriageway' cannot be achieved.
GSV doesn't give a definitive answer because it's out of date. So, get your camera out and take photos of the opposite side of the road, say spanning a length of 15-20m either side of the point immediately opposite the steps.
If there's no corresponding dropped footway then the council are on to a loser, they might also be if an adjudicator holds that the utility of steps excludes sufficient persons as to not apply to 'pedestrians'. But this aspect hasn't been tested in court as far as I'm aware and therefore I don't think that it's possible to state definitively that steps as such fail to meet the test.
And OP, as the prohibition is 24/7 and the exceptions of alighting/boarding and use of a BB do not apply, then placing yellow lines can actually mislead, although in practice it's often done.