It's more like batteries going down in the field. BUIS need very little maintenance to run reliable if any.
I run a A2 front base with 24/7 Night sight and Daniel Defense A1.5 Rear sight. I love it, works perfect and probably will never fail.
Yes, most RDS and mil-spec scopes are built though, but glass breaks, buttons wear out, batteries die, water kils it ( if optic is already compromised).
ALL reasons why I would have BUIS on.
Range toy is another story.....
"A well regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed."
"Between your faith and my Glock 9mm I'll take the Glock."
- Arnold Schawarzenegger (End of Days)