Why do carscome with auto start/ stop, if no one likes them? And it bad for engine?

It's fine in mild or full hybrids as long as the ISG is powerful enough to start without struggle or delay and the computerized clutches don't suck. It's annoying as absolute *fuck* if the starter is just a beefed-up regular starter that makes the old-school cough and whizz sound. Wear isn't a significant concern if the restart is smooth and the oil is good at staying in place. Which it is designed to do. The main reason why you pump oil through an engine is so it has an opportunity to cool and that's not necessary when stopped. For a lot of us oldies it feels like the engine has stalled, which takes a lot of getting used to. I can definitely understand the decision to just not get used to it - what do you mean it's supposed to do that and I should just push the clutch when I'm ready to go? Get off my lawn! Anyway the main benefit of mild hybrids is they can do stop-and-go traffic without burning fuel to idle. They can avoid enriching the fuel-air mixture to provide moderate power at low speed, which saves fuel and is better for emissions. In theory the technology can also hide turbo lag and make shifts happen more quickly, but they're nowhere near as responsive as a full hybrid or battery-electric. Mostly the tech is cheap and unloved and not any worse than a traditional fuel burner except that it sounds like it's constantly stalling.