I have been running Windows 10 for a while now and every other day or so, I get the Security and Maintenance notification shown above regarding "disable apps to help improve performance".
My machine has 12 cores and 32GB of RAM - I really am not experiencing any kind of noticeable slowdown, and all the apps running in the background are ones that I explicitly want to be running in the background to improve performance in my daily workflow. When you click on the notification it takes you to the Startup tab in Task Manager, where you can disable items in the startup, which I don't want or need.
After a bit of hunting around, I have finally discovered how to disable this notification from appearing any more. The process is very simple once you know it!
You will immediately see the "problem" highlighted in the Security and Maintenance window: