Well, developing a tileset at the time meant you more or less had to start working with the .json list someone else was using - I started with hoders and expanded that as I maintained it, and I think some current tilesets continued on with mine.
Either way, that was just to have a starting point, a loooong list which took up 2-4 lines of code for each item including separation brackets on either side. At the point where I last updated that list had 12,000 lines.
Now, the way it worked was that a item exists in the game; say a book on cooking titled “Cooking yo.” and that had to be declared to the book tile. Then another book called “Cooking You. Yes, you.” had to be declared to the book tile as well.
Basically there’s a whole lot of bloody books in this game, same deal applies to ammunition, electronics and certain food items.
Then there are of course additions, each experimental brings something new on a daily basis, and when all this is released to the stable release, there are likely a tonne of untiled things running about. And that counts for items, bushes, berries, creatures etc. etc. etc.
You had to look for these in the github repository, search up their ID, add that manually to your Json and then tile the thing. Rinse and repeat many many times.
There was basically just too much labour involved in the process. Almost nothing was automated and sometimes the ID’s for things you had tiled would change because it was more in line with the coding standards. - Which by itself is fine, but the disconnect between tileset-makers and coders working on the game meant you often only found out about that after someone reported the bug to you.