[Possible methods of mitigation] com.apple.hiservices-xpcservice (Not Responding)
I first noticed com.apple.hiservices-xpcservice hanging in 2021 when I thought the cause was 1. Mac waking up from sleep 2. Mac keeping specific apps in the background while it slept.
Some users thought connecting an external monitor was also a factor but I never tried it.
I've found a lot of people on the web with the same problem, but Apple has never fixed it or responded to users, even though it's been around for about a decade or so.
Some users have claimed things like the keyboard lagging or the fan suddenly running at high power or heating up, while others believe that the program hangs with no detectable side effects.
I recently discovered a way to alleviate this problem by "not opening the Activity Monitor app".
In my experience, Safari stays running while Mac sleeps, and Mac wakes up and checks the Activity Monitor app, the service hangs. However, if Mac is woken up, exits Safari, and then goes to open the Activity Monitor app, the service does not hang.