Isn't this because most waste is passed onto the consumer?

I can't buy singles of most vegetables in my local supermarket (part of why I don't go there unless I need to). I don't need 12 lemons for the one recipe that needs zest of lemon but I have to get them and find ways to use the others.

If I can buy singles, it's deliberately priced so you have to pay way over what you should. Most people can't afford that or aren't wired to pay more for less when less is actually appropriate for their needs.

Then there's 3 for 2 deals, which seems to always be on stir fry kits that you have to use right away.

My country also recently stopped putting use by dates on food, which means stuff that previous would have been wasted in the store still gets sold and so more likely is wasted at home.

Maybe if you count the inedible parts of the food you buy as "waste".
Sorry, but I'm not into Avocado pits.

Per household or purchasing body (as in a store or restaurant) I have my doubts. Never in my life have I dumped 3 dozen perfectly edible sandwiches in the trash on any given day.

There are a lot more households than there are stores or restaurants so in aggregate total homes may make for a greater sum, but that's the same kind of logic they use to say people need to all switch to paper straws and forgo the AC in summer while the rich fly about in personal jets and rockets for a joyride.