Charisma or however you want to define it plays a part in human interactions, it's the way we're wired up. Like you though, I have no wish to hear a celebs view on pretty much anything outside their field. No matter how passionate is is to them.
It's true, single use plastic is almost unavoidable...it's also true I'm an extreme case, I question everything I buy and do my best to avoid plastics but they're everywhere, often hidden in products that we buy not realising their plastic content.....I mean to say, tea bags? Who was aware that they reinforce paper tea bags with plastics? These days I buy loose tea and own a stainless tea strainer...I even use bamboo tooth brushes (I like them much better than plastic ones and they're really cheap)
There's not a lot we can do about it unfortunately, so much stuff comes in plastic and you can't reuse all of it. It's going to take legislation to force changes through and that's just to reduce rather than stop it.