I’ve also felt, and probably said a few times, that the absence of these on TV these days is probably detrimental. The fact we used to have such features probably reflects it’s always been a problem since the advent of consumerism, take aways and ‘disposable’ packaging which takes years, decades or longer to biodegrade.
The old public information films often did it with a bit of humour, especially the cartoon chap and his wife Petunia.
These days information comes across as a bit preachy whenever we are told things by the government.
I bought a collection of these on DVD a few years ago.
Many bidoegradable plastics are not really what people think, in the sense that they decompose but not necessarily to simple naturally existing compounds, but chemical breakdown products which are not naturally occurring. at all.