Drop off/pickup points are the answer, disabled drop off/pickup might be redundant but could make sense in certain high capacity situations.
You have to actually put those drop off points on every street corner, though, and is the lowest priority for city planners, and gets rolled out at a glacial pace over decades--while disabled people have needs today. Having been forced to confront how well designed our infrastructure is for disabled access and put it to the test, I can tell you that a lot of existing ADA infrastructure can best be described as "performative" and a lot of it is entirely missing.
... bike lanes are not the only thing that creates this issue. Any road that lacks parking, with or without bike lanes, will have the same problem. Even when there is parking, all of the parking spots may be occupied. In both cases, people may have to walk a few blocks. While they may be grouchy about the lack of (sufficient) parking, you don't see many people blaming motorists for placing a burden on the elderly.
Finally, it is always possible to make accommodations. Having a carve-out for loading and unloading taxis will do far more for safety of everybody than letting people stop anywhere in bike lanes. It is also possible to have exceptions for people with disabilities, as long as non-disabled people don't abuse it.
In general though, special affordances for parking and dropping off disabled passengers is only given to those with a blue badge. AFAIK in general taxis carrying disabled passengers without a blue badge have no more rights than any other vehicle. Only companies that specifically care for disabled passengers can get their own company blue-badge rather than relying on their passengers having one.
Because we also have streets with a car lane and a bike lane with a solid line where it's forbidden for any other vehicle to enter or stop there, so of course I had to explain to a few drivers what are the rules they should alrady know and follow.
Double yellow lines (waiting / parking) are different to bike lines however. If a bike line is separated from the road by a solid white lines, motorised vehicles are forbidden from entering at all. If you want to load/unload or drop off passengers, you need to do that somewhere else. If the highways agency considered it safe for vehicles to block the cycle route in that place, they'd use dashed lines instead.