I took on a glass job. That I strongly didn't want to do because it was already done. Person wasn't happy with the final results. Cost me hundreds of dollars & wasted time. Refunded the persons money in full, & they still complained on Pinside about it.
I do what I can to supply glass, & custom orders. Don't care how many people are doing the same title. Try to do the best for my tiny market. That being said hats of to all the big producers, & the small demand ones around the world.
Color variations, glass or plastic that gets a fine scratch, & mistakes by anyone or any machine in the process. Adds to more costs & delays. Last week I rejected a tempered glass order because the LOGO was stamped to the corner of every one. They checked & verified that it was their mistake. That delay is another month + for customers to wait. Add in the cost of cardboard box(s), tape, printing labels, packaging, & dealing with email is also huge for time. It even takes weeks locally to get our custom cardboard done, but they do a good job!