I was told a long time ago, I think from a sculpture professor, who could have stolen the quote, that the mark of a great craftsperson is not how well they make an object but how well they cover their mistakes.
Also, I don’t know if paper was expensive in the 60s, I don’t think it would be, but it wasn’t in the 80s and another professor taught me paper’s cheap, 1 idea per page. And again, it there was an errant marker line, fix it. There is no Ctrl-z with analog.