There are several reasons for this and all are down to CCC and their poor execution and communication with respect to recycling.

For example...
They will refuse to empty a bin and not leave information telling you why!
They couldn't make their minds up about recycling butter cartons.
By cutting the main bin emptying cycle they expected people would recycle more, but that has spectacularly backfired on them.

As regards communication, CCC don't understand their electorate. The city has a large percentage of recent immigrants, many don't understand the use of a basic bin, never mind the 4 we have in Coventry.

Note: I say we have 4 bins, but officially I only have two, because the others were never delivered, despite Mrs R. giving the council earache about it. - Mrs R. did eventually obtain a recycle bin, but she's never explained to me where it came from.

Strange how CCC can't find my house when making deliveries, but the postie can find it when delivering their ever exorbitant council tax bills!

It's not good enough, really: https://www.coventrytelegraph.net/news/coventry-news/recycling-coventry-and-warwickshire-15208750