Hit a pot hole a few times, and you don't know what internal damage you do to the tire, most people don't check brake and other lights, nor fluids, most don't even put winter tires n (depending on your region) a lot of people get in there car and drive, they assume it is all ok as there mechanic has told them so, most just put in gas and away they go.
Safety is about dealing/planning for the lowest common denominator, i.e the nut behind the wheel.
Get into a minor fendor bender and no-ones the wiser, kill somone or some people, police and insurance will be all over your car to ascertain blame. If you couldnt brake in time, because there was something wrong with your car, assuming you were not texting, drunk or doing your makeup, you are in a whole world of hurt.
Anecdotal evidence is an oxymoron and not data, just because you have driven on tires for 15 years, or your uncle bob has does not make it so.
Most auto manufacturers recommend replacing tires over six years old regardless of tread depth. Some tire manufacturers like Michelin and Continental give a 10-year limit. As rubber compounds age, they deteriorate and become weaker like other rubber and plastic components on your car.
If you wanna cut costs, tires are not the way to do it, your tires are probably one of the most important things on your car,
Generally, the overall size of each contact patch is no larger than the size of your hand, that's scary.
If you wanna be frugal, put in the cheapest gas you can, drive with the AC off, stop buying coffee from the drive through, use a cheaper hooker
but for the love of God, don't try and get a few more KMs out of a set of tires, it aint worth it.
I pay attention to my car and it's maintenance, I am a bit over kill and OCD, but then I don't want 50 grands worth of BMW failing nor costing me money.
I do appreciate times are hard people driving $200 beat up 25 year POS cars, so trying to justify 400 bucks of new tires is hard, I get it.
Heck my first car in Canada was a 12yo Dodge Neon,
it slowly fell apart but car's tires were impeccable, probably worth more than the car ?
Ferried me and my baby till she was 4 , which was the most precious cargo ever in that car, so no comprmises,
that was until some douche side swiped me on the 401 and wrote the car of.
Got $3,500 off insurance, which was probably 3500 more than it was worth LOL,
I guess everyone has a POV and argument for and against, nothing more I can really add that has not been said
PLEASE DRIVE SAFELY