Open proxies? I heard about this more than a decade ago, but why would anybody in 2022 run an open proxy? Or are these open proxies unintentional, i.e. misconfigured?
Many of them are unintentional: a device sitting on the open internet has some vulnerability and gets exploited. Bad guy sets up a proxy on the device and uses it to click a bunch of ads using bots, or crawl Google results, or launch attacks, etc. Or, as mentioned below, they could simply be the result of misconfiguration.