I hate the phrase 'virtue signalling' and find it says lot more about the person using it than the people its directed at
I think it's an excellent, very descriptive, expression for certain types of behaviour and enjoy using it! I don't virtue signalmyself because I don't have any virtue to signal (though I do have a hybrid car now, but then, I am fortunate enough to be able to afford one).
But I also agree that every little helps. Every plastic bottle that isn't used, mounts up. Same with plastic cups. And yes from acorns grow oaks and all that. There is SUCH a lot of plastic rubbish in supermarkets though so just getting rid of plastic cups is a very small acorn.
I think M&S is the worst though. For example croissants. In Waitrose there is a plastic bag but a cardboard tray. In M&S the whole thing is plastic. And then they have their 5 grapes in a plastic cup for lunchtimes :( As for their stupid promotion with the plastic toys...why would you do that?
Actually I will virtue signal - but as an illustration. I like cheese and eat rather a lot of it. I used to buy plastic bags to put it in once it is open so it doesn't go funny in the fridge. It has now occurred to me that I can reuse the bags that cereal comes in, or indeed the plastic bags that loaves of bread come in, instead. Not perfect but I am not longer buying extra bags. And in the end that's what matters - awareness, small changes of behaviour leading to bigger changes.