I'm a manager now but definitely held a variation on this "people are idiots" view when an IC and younger. Question: are all your coworkers idiots? No? then why would all the work done before you be the product of idiots?
I found it really valuable to approach scenarios where the initial response is "how could this possibly happen?" as a cultural anthropology question. It turns out there were many rational decisions made, most that I would have gone along with that brought us to what we see today. My coworkers are actually really good, some of them who manifested what we see today are amazing. Many are crafting code, making thousands of microdecisions without perfect information or 100% clarity across a large organization, reacting to changing markets and directions, client needs, shifting priorities, executive decisions, technology changes... the list goes on.
This is all my way of saying there might be many reasons for any of these choices, and you'll help your own cause - and happinness - if you step back from your zealotry and take an empathetic approach that's less binary.