My guess is that the idea of matching sets goes with the industrial revolution and mass production. For most of history, most of our ancestors would not have replaced anything that wasn’t broken. Most people would have put up with broken things, or fixed them, or only replaced what was broken. The idea of matching crockery is a pretty weird one when you think about it in terms of how we use resources. Matching kitchen furniture. Matching bathroom stuff – these things are bulky and costly to replace, but so often if one goes, the lot has to go.
Of course, this whole approach serves capitalism very well. If we feel tatty and shameful with mismatched items and are persuaded to throw everything away and get new ones any time a single thing breaks, we spend more.
I recently went round this with the kitchen floor. A number of the vinyl floor tiles were breaking up and not fit for purpose. Doing the whole floor was clearly going to take a lot of time and effort, so neither of us got round to it. Eventually it dawned on me that there was no need to do the whole floor. No need to take up perfectly serviceable tiles in order to replace them. We bought a single pack of tiles, removed the damaged ones, inserted the new ones – a job that didn’t take Tom very long at all in the end. A small amount of unusable material went to landfill.
We now have mismatched floor tiles in the kitchen. It’s perfectly functional. It looks like what it is.
So much of it comes down to what we think is desirable, acceptable, good enough, versus what we think will get us judged critically. If looking overtly green was considered your sexiest option, it would be persuasive. If you thought people would look on you favourably for waste-avoiding choices, then chucking a whole bunch of things away because one thing was damaged, would not be even slightly attractive.