It is also considered an endangered craft. Some scientific instruments, if broken, cannot realistically be replaced in any reasonable time frame (or sometimes even at all).
People who take up glassblowing as a hobby are closer to being crucial to the world economy than most.
Just something to chew on.
It isn’t like mind blowing or anything. But it sure is something.
I feel like if a mostly self-sufficient and ecologically neutral economic unit were to be made, glass making would easily be in the top 10 most important occupations.