I hesitate to chime in here, but…
Yes, Epson printers “waste” some ink in keeping heads cleaned. But, I don’t quite understand why no one complains about Canon printers “wasting” print heads for exactly the same purpose. Mapping out nozzles when they can’t be cleaned leads to the need to replace heads after a few years, and it’s a big expense. I don’t know if they “waste” less ink in their periodic cleanings. but that may well be the case. I’m honestly not sure which system is cheaper, but it’s certainly not as clear cut as saying one "wastes" ink and one does not.
I also do not consider all ink that doesn’t end up on paper “wasted”, since it performs a required function without which the printer will not function. Nozzle and head replacement perform the identical function in other brands, and it's not as if they use zero ink in attempting to clear clogs before nozzle replacement is required. The only difference is whether the money goes into ink or ink+ nozzles and heads. When you spray ink from nozzle that’s thinner than a hair, clogs are going to happen no matter what system is used. Pumping ink to clear the clogs is just one way to solve the problem, and replacing clogged nozzles and print heads with new ones is another. The simple fact is that piezo nozzles (Epson) are very expensive, so the nozzle and head swapping method is not an option. Flushing the nozzles with ink clears clogs with the least cost and is just what makes sense. Thermal nozzles (Canon, HP) are relatively cheap, and replacing or mapping them out is what accomplishes the clog clearing task with the lowest cost on these printers. It’s simply what makes sense if you’re using thermal heads. One method is not particularly better or worse. It’s a fundamental difference in the technologies, each of which has distinct advantages and disadvantages. There's a lot more to selecting a printer than ink usage, which is indeed a small part of the cost of photography and print making.