Lifts are a whole other issue! It's good if your relative is happy to use them, but my mum is totally phobic of them and also became too confused to use escalators. This meant we had to stop going to the cinema, for instance, which is a multiplex in a pedestrian precinct with no fixed public stairs, just one very steep, glass-sided escalator with flashing lights in the treads, and, presumably, a lift for the physically disabled - all too challenging for mum.
Yet I'm sure the above qualifies that complex as "accessible" because of the lift and pedestrian walkways!
Sadly, we had to stop going into the town centre at all, because of the parking situation. The only places we could go together were pubs or out of town restaurants with a car park directly outside. The theatre (which she could no longer follow, but still enjoyed in the moment) has a multi-storey car park directly behind, which for most people is very convenient - but no on street parking that's not "disabled", and again the walk down from the car park amid jostling crowds and car noise, or through neighbouring streets full of drunken stag and hen parties at night was just too much of a strain.
Physically disabled people may also be confined to their homes because of similar obstacles, but at least their needs are publicly recognised now in law, if not always in practice; but those with dementia (and their carers) are often hidden casualties of town planning.