It does make sense. If you can’t do what (for want of words) an able bodied person is able to do, then it has to be a “can’t do it”.
If you say you can do it- they’ll just accept that you can do it . They’ll not look at the fact that it’s only sometimes, dosed up on medication, taking longer than you would if you didn’t have the condition, in pain, probably causing yourself additional pain and further issues (possibly accidents, like falling down) in the process.
EG my mum could theoretically walk to a bus stop close to her home. About 4 minutes up hill walk for me. She could force herself, would be in crippling pain, would need to keep stopping for breaks, take possibly 30 /40 minutes at least to get there. She would then have to be carried/lifted on to the bus. She cannot use a wheel chair /sit for long periods due to pain. Plus she can’t pull herself up. She either stands or leans against things.... the question can you walk X distance? The answer is no. Because it’s not practical, or reasonable to expect her to go through all that to do it and when she got there she couldn’t get on the bus anyway! She’s also very depressed about it as she has friends her age who can do these things. She cannot take medication due to her IBS and heart.
She uses “grabbers” to pick things up off the floor. She can get dressed and shower to a degree, takes her ages, she can’t dry herself properly and has equipment to help her, she cannot put her socks or shoes on. She can cook a meal .... but this is quick meals like soup, toast, boiled eggs, micro chips. She couldn’t cook a roast dinner or anything that requires preparation or needs to be watched for example. So ‘can you cook a meal’ - the answer is no. It’s not reasonable or practical, plus soup and microchips isn’t a meal! - but mum would class that as a meal and say “yes, I can cook a meal” - then she wouldn’t get benefit. Does that make sense?
You have to mention everything you struggle with.