The point I think is, those you've mentioned is life long term disabilities, Tinnitus can go tomorrow, but you know it probably won't, but Tinnitus, if you put your mind to it, is just another "sound" that you hear.
Tinnitus
can cause disablement. Usually (at least in Finland, so I'm making a generalization here) the cause of disablement can't be solely tinnitus, however it very well can be mentioned alongside with depression, stress, anxiety, etc. that can accompany tinnitus. There is a ICD-10 code for tinnitus and as far as I know it is "H93.1 Tinnitus auris".
So one's disability's reason could be:
H93.1 Tinnitus auris
F33.2 Major depressive disorder, recurrent severe without psychotic features
While I think most people will habituate and tinnitus will not cause permanent disablement for many, there are always the exceptions. It's very well documented that tinnitus can cause other mental problems and simply make it impossible to continue at one's work. And disability retirement can ensue.
Sometimes I think about people whose tinnitus is ever changing. Multiple sounds. Doesn't stay "constant". I'd imagine habituation and living with that would be way harder than for the more usual high yet constant pitched ringing.
In summary, tinnitus is such a subjective condition and while the physical reasons for it vary, so does psychological aspects. Pardon my french but it can be a bitch to tame.
Speaking about its disablement factor... there are recorded cases of suicides because of tinnitus. I think nobody can know how the other person taking that action really felt and judging them is futile. Of course it makes me sick when I read about tinnitus taking lives, because tomorrow is always unknown and situations often improve, plus with good pharmacological and psychological therapy these dark thoughts can often be helped.
My answer to the question thus is: It can cause disablement. How different countries mark the cause on the papers differs. For some, while on the disablement leave/retirement, tinnitus can improve and they might decide go back to work.
Disability isn't always a lifelong sentence.