Building those older LEGO sets reminds me how bad things were back in the eighties. The instructions were quite challenging to follow. Not because they weren't detailed enough, but was sometimes hard to figure put those details.
The basic idea was to just figure out the difference between two consecutive pictures of a build step. But there were no idea how many differences you were supposed to spot. When you finally figured out all the parts to add there were still some challenges figuring out the exact right position and sometimes even colour. Some darker colours also made it difficult to actually distinguish the parts in the pictures.
Since then there has been two major improvements to the overall instructions. First, they added the list of parts needed in esch step and then later highlighting of the new parts in this step. Even though the newer models are usually more complex than the older ones this makes them more easy to build. At least on the part where you tey to figure out what to do next.
The colours though are still a challenge. Not the least because the ever increasing amount of different colours, but the fact the printed colours don't always match the real world ones due to printing quality restrictions related to colours. This hasn't even gotten any better in the digital world.