Things have certainly got worse in the last 25 years. We don’t have a ‘right to roam’ enshrined in law, but on the other hand the trespass act defines trespass as failing to leave when asked (in person) to do so. So you can legally wander, so long as you are not causing damage, but that doesn’t mean you’ll be welcome.
The legal vs formed road thing is an absolute pain. Blame changed attitudes, or blame improved mapping? I’d say very few farmers knew that the legally gazetted roadline and their farm track did not follow exactly the same course until the ability to superimpose property boundaries over airphotos came online!
I really hoped that the Walking Access Commission, when it was established 10 years or so back, would resolve all of these through negotiated land swaps backed up by the threat that they have the ability to impose public works act orders to make it happen (ZL’s compulsory purchase order legislation). But they seem to have preferred the ‘long game’ of dialog and agreement, and getting no landowners off-side: agreements and co-signed easements instead of resolving the actual inaccurately defined property boundary issues. Waiting for farmers to die or retire so that they can try again with the next generation.