...hmmm. The solution to the problem of "up to seven recycling bins" is to...
legislate to require a given additional bin. I don't see the joined-upness of that, at all.
And I actually thought I'd check various kerbside systems, the other day, for semi-random[1] UK locations, and here's a roughly reworded subsample of that:
Birmingham: Standard bin, Blue bin (cardboard/paper in insert, plastic/metal/glass in main) and/or Blue box (paper)+Green box(plastic/metal/glass)
Cardiff: General, Recycling(?? must be usual things apart from->), Food, Glass, Garden
Chelmsford: Black (non-recyclable), Grey (food waste), White sack (paper), Separate white sack (cardboard), Brown (garden), Green (cans, glass, small electrical, clothing), Clear sack (plastics)
Dover: Grey wheelie (non-recyclable), Kitchen-caddy (food), Blue-lid (glass, tins, plastics), Black box (paper, cardboard), By subscription (garden waste)
Edinburgh: Grey (non-recyclables), Brown (gardening waste), Other grey (food, no liquids or packaging), Box (glass/small electricals/;separately packaged batteries and fabric waste) Green (mixed paper/cardboard/plastic containers/'tins and cans and foils')
Glasgow: Standard non-recyclables, Blue (paper/cardboard/plastic/cans), Purple (glass), Brown (garden and food waste - houses), Grey (food waste - flats)
Pickering: Black-and-green (non-recyc), Green (plastics/tins), Black container (glass), Blue (paper/card), Brown (garden)
Lancaster: Grey-lid (non-recyc), Red-lid (cans, plastic, glass), Yellow-lid (paper-cardboard), Green-lid (garden - subscription)
Sherringham: Grey (general), Green (glass, cans, foils, plastics, cardboard/paper), Brown (garden, christmas trees)
Thurso: Green (general), Blue ('recycling' - to become two different containers next year), Brown (garden - subscription only)
Truro: No regular bins(? ...but seagull-proof sacks available), Orange bag (cardboard), Black box (glass, textiles), Red bag (metal, plastics), Blue bag (paper)
((As one of my regular walks takes me past properties in three seperate districts/council-regions, I get to see three slightly different 'bin regimes'. Though none of them either excessive nor, to my layperson eyes, insufficiently segregated, for all their differences. None of the three currently have Food Waste (unless it's in the garden-waste bin, where there is one/it's allowed/subscribed by the local scenario), but I really don't know how much food waste I generate myself. Practically nothing, once I've rinsed out packaging enough to qualify it for whichever of the three bins I currently might roll out myself and put out the odd scrap for wildlife. I can't see me using an actual food-bin at all.))
[1] ...nearest to where I 'threw my darts' when trying to hit various regions. But as I'm neither a brilliant shot nor a totally wild and unpredictable one, probably not as representative either as I'd hope or intend.