I have always made an effort to take time off work and go to class assemblies, plays etc. The same few children get the main parts, because they are reliable and do a good job. My son (8, Y4) gets the odd line but, like most of the class, is essentially stage furniture. He is used to this situation, and not that bothered.
This time he literally doesn't have one word in the entire play. I am happy to send him in dressed as a pirate so he can stand behind the boy who has all the pirate lines, but I am about to wipe out a lot of A/L over Christmas and I really don't want to book yet more time off to go and watch other people's children perform.
My friend says I will regret it and DS will be mentally scarred for life. Will I? Will he? Or does there come a time when you can say "If he doesn't have an actual part it's fine to skip it"?