Swipe down to search in the Google launcher? My phone runs a Pixel Experience ROM which has a stock Google Launcher that I like a lot. I do not wish to change launcher.

I used to have a Huawei device, and it had a feature that you could swipe down on the home screen and it would search the enitre phone for apps, contacts, etc. I believe iOS has a similar feature.

Is there any way I can get this same feature on the Pixel Experience ROM, without switching launcher?

I have root, Xposed, Magisk, etc. My Android version is 8.1
You can't get that feature on Pixel Experience until the developers make for it. But you can still find apps on the Google Play Store which have similar search utilities as you said without changing the default launcher.