IMHO if you ride audaxes you should enter into the spirit of it and fill in the card.
Yes, I see your point, but ...
I remember one where the info was a postbox, near the end of a very hilly route on which I made slow progress. I rode past where I thought it should be, up a big hill. No sign of it. I must have missed it, so I turned back. Down big hill, added a bit extra for good measure. Back up hill. Still no postbox. Gave up and carried on. Asked another rider. They couldn't find it either. Another time the question was was "name of pub on the left", I memorised pub name (Red Lion or whatever) as I rode through the village and carried on. Got to the end only to be told by the person at the table "No, the Red Lion is the one on the
right, the question is the one on the
left." In both cases I got another rider to tell me the answer. Yet another one was "colour of roof of xyz". My colour vision is poor, so I got it wrong. And another was "what material is the gate at abc made of". I remember getting a bit annoyed about that because it was made of some kind of nondescript stuff, and I didn't want to be hanging around in someone's gateway.
These experiences made me question whether I want to bother with infos ever again. After all, I'm not an AUK member, I don't collect points, I just go on them because they are nice rides organised by nice people. If I worry about infos too much it can completely spoil my enjoyment of the day. So now, I'm a bit more chilled about them. If it's easy, I'll memorise it. If it's not, or if I forget, I'll do without. If I don't submit my card, it's less admin for them to do (but I do make sure I always let them know I'm off the route when I've finished).