Pinstriping is not dying much, if at all. It's just gone the way of "real" sign work.....being replaced by vinyl in a lot of places. The vinyl merchants can purchase a CD with pinstriping patterns, hit a button, and cut 'em out.
It takes work to learn to pinstripe, and many "want it now". I've been doing sign work and striping for over 30 years, and still enjoy every day at work. It's fulfilling to see a few drops of paint come to life on a vehicle or just on a panel.
I'll dig thru some pictures and see if I can post some of them. If you've got an interest, go for it. It doesn't cost as much as a video game to get started. It just takes practice, practice, practice. You can buy an old fender or door skin from a junk yard; or just a piece of plexiglass. Stripe a design; wipe it off with thinner; and do something else. Above all else....have fun.