In my own workplace, it's sometimes resulted in massive rabbithole searches along the lines of "this doesn't seem right. Why would this even be designed this way if it wasn't intentional?" Which then becomes asking even more senior devs who had been there for decades to scour decades old emails and/or hitting up another decades senior dev who's now on another project on the other side of the country to check their emails until we eventually figure out why it was, in fact, intentional.