Yup things like "household repairs" are IIRC done if you're eligible for several of the income related benefits and it's basically a necessity to keep your house habitable or your disability requires that adaptation. And it's not exactly free, they put a marker on the house so you cannot sell or rent it out for at least 7 years.
And most of those things are related to the actual disability, for example they won't pay for your new kitchen unless you need major adaptations and it's the only way to keep you in the house, but they might pay for a new stairlift or bathroom to be converted to a wetroom, or something like a roof repair.
Someone, somewhere realised that if someone owned a property it was probably cheaper long term to help keep them in a property they owned and was already largely suitable than force a family with a disabled (or elderly person) into a new home that would need adaptations again.
My parents had to get one of those grants when my mother had her failed hip op 20+ years ago, basically my parents didn't at the time have the money to pay for a stairlift and the wetroom conversion and the occupational therapist required to be fitted, and any other property they moved into would have been smaller/less suitable and required all the work that my father and I had already done* to be redone as well as the wetroom and likely stairlift (not many houses come with a full wetroom bathroom), and the council just did (without it being charged on the house) several other minor jobs as they were "standard recommendations" by the occupational therapist that basically took a council staffer a couple of hours.
*For example we'd already put in a slope at the front, fitted handrails inside and out, raised the path at the back and put in much bigger and shallower steps so my mum could get in and out the back door more easily (the council replaced our backdoor handrail with one that met their standard) and allowed the wheelchair to be got into and out of the house by the back door and built a custom shed for my mother to park her electric mobility (that we paid for not "free" or "motability") scooter in for storage and charging (I set the shed up with electrics and automatic lighting inside and out).