The only boots that I can think off, which are really easy to clean beneath a tap are rubber boots. These, however, are mostly not very suited for hiking: most of the available ones are made rather cheaply, provide neither good soles, nor good comfort or stability. And of course their breathability is essentially zero.
Unless you buys some very specifically made hiking rubber boots (they exist) I would not advise to go down this route.
IMHO caring for your hiking boots is just part of the deal... But then, I also don't invest a lot of time here. I maybe roughly clean my boots 1-2 times a year and give them some new coat of wax (I have leather boots), but that is it... Saving those couple of minutes per year wouldn't be worth it to me to forgo all the additional benefits of decent hiking boots.
But as a kind of frame challenge...
How dirty are your boots getting, or what kind of dirt are you trying to wash off? If my hiking boots get really muddy then I just rinse them off using a hose while wearing them - this mostly prevents water from entering through the top, and if I do it quickly the also don't get soaked (actually, if you have good properly-looked-after boots they can take quite a lot of rinsing without any water entering).