try, fail, learn, try differently. - James Clear

Early feedback is usually better than late criticism. Delaying the conversation or stringing someone along with indirect feedback won't make them feel better once the real issue is finally addressed. Nobody likes getting bad news, but everyone appreciates clarity.

Motivation is overrated, environment often matters more.

Be kind. You should do it simply to be decent, but do it even if you're a ruthless mercenary because you have no idea where people will end up in 10 years. The balance of power is always shifting. People will surprise you.