I have so many pet peeves I could probably write a book about them.
One I came across lately, when somebody painting a room, exterior wall, etc spends a ton of effort masking around an electrical fitting, invariably making a mess and getting paint on the thing anyway instead of simply removing a couple of screws and getting it out of the way. A couple years ago and elderly family friend nearly had her house burned down because the painters wrapped plastic around a halogen motion sensor flood on the side of the house and taped it up, then when the sun set something triggered the light and it set the plastic and then the wall on fire.
Magically shrinking products and deceptive packaging to try to hide cost increases, for example a "gallon" of ice cream is nowhere near an actual gallon anymore. Especially when they try to spin it as something good for the consumer ("These candy bars are now only 100 calories, they're healthier!")
Outsourced tech support handled by people who have thick accents that are difficult to understand. Nothing against folks who don't speak my language fluently but when your entire job is to have a spoken conversation with me it is really an important skill for that particular job.
When software tries to guess what I want and be helpful, more often than not it is wrong and creates additional work rather than saving me work.
When software updates are automatic and rigidly enforced and nag Nag NAG NAG or even auto-reboot regardless of what I'm doing.
When software is excessively buggy, half baked, shipped half finished on the pretense that it will be updated "later" and I am expected to be the QA of a product that I'm paying for.
When a device containing a battery is sealed such that it is difficult or impossible to replace said battery.
People who ride my bumper when I'm driving, then aggressively pass me only to drive slower than I was going when they were behind me.
When people can't figure how how to get up to speed and merge onto the highway, making me either stomp on the brakes or floor it to get out of their way before they run out of onramp.
When I am not allowed to do something because some other idiot did it, found a way to hurt themselves and then sued over it.
When I hear of companies throwing good equipment into the scrap bin instead of making it available to someone who can use it.
When software moves to a subscription model in place of the option of a perpetual license.
Robocalls. I don't think I need to explain that one.
Excessive political correctness, the euphemism treadmill, people going out of their way to find something to be offended about or outraged over.
Corporate HR that actively filters out so many excellent candidates, passing along all the ones who's greatest skill seems to be gaming the system and sprinkling their resume with all the right keywords.
Well-meaning but poorly thought through regulations that invariably come loaded with unintended consequences.
I could go on but this is probably enough, contrary to how it may appear I am not an angry old geezer whose favorite pastime is yelling at neighborhood kids to get off my lawn.