In the UK at least Apple has a subscription-based iPhone upgrade program [1] to get a new iPhone every year. Makes sense as they want recurring revenue, but it does seem wasteful to promote that type of consumer behavior.
Yes, and in fact getting a trade-in price is dependent on having a relatively current working phone. They don't give you a trade-in for any random piece of broken metal, silicon, and glass.
[1] https://www.apple.com/uk/shop/iphone/iphone-upgrade-program