It might be related to how these apps cause the OS to boost the CPU cores or schedule those background tasks on the more powerful (and higher power) cores instead of the efficiency cores. I’ve seen the opposite issue on Linux and Windows with newer CPUs not boosting high enough.

Apple’s own apps might have had the same issue, which would explain why the update was hundreds of megabytes instead of just the kilobytes or megabytes need for a core os update.

Then again, I haven’t worked on os stuff in a long long time, so I’m pretty much just making it all up.